This was CNBC's live blog tracking developments on the war in Ukraine on sept.6, 2022. See here for the latest updates. 

Russian officials continue to threaten to cut Russia's energy supplies to the West, with Moscow warning it might ship more oil to Asia when a price cap planned by the Group of Seven comes into force.

Meanwhile, a top Gazprom official has said that natural gas supplies to Europe via the Nord Stream 1 gas pipeline will not resume until Siemens Energy repairs faulty equipment.

Gazprom halted all flows through the pipeline on Friday after it said it had detected an oil leak in a turbine engine at the Portovaya compressor station and said it would cut off supplies until the issue is fixed.

Siemens Energy issued a statement on Saturday saying the leakage is not a technical reason for stopping gas flows through the pipeline.

In Ukraine, President Volodymyr Zelenskyy commended Ukrainian fighters who destroyed a Russian missile warehouse and vowed a response to an attack on his hometown of Kryvyi Rih.

Video shows aftermath of Russian airstrikes on Kharkiv city center

Source: Metin Aktas | Andadolu Agency | Getty Images

Ukraine's northern city of Kharkiv came under air attack on Tuesday, damaging what appear to be civilian buildings in the city center.

Russian attackers and Ukrainian defenders have continued fighting on the ground in rural areas outside Kharkiv since Ukraine began pushing Russian troops further from the city in May. But Russian aerial attacks continue on the city, which is close to the Russian border.

— Ted Kemp

Six vessels depart Ukraine carrying 129,538 metric tons of agricultural products

The organization overseeing the export of agricultural products from Ukraine said it has approved six vessels to leave the besieged country.

The Joint Coordination Center, an initiative of Ukraine, Russia, the United Nations and Turkey, said that the vessels are carrying a total of 129,538 metric tons of grain and other food products.

The ships are expected to depart tomorrow and are destined for Spain, Kenya and Turkey.

— Amanda Macias

Biden congratulates U.K. prime minister Liz Truss

President Joe Biden congratulated newly elected British Prime Minister Liz Truss.

"I look forward to deepening the special relationship between our countries and working in close cooperation on global challenges, including continued support for Ukraine as it defends itself against Russian aggression," Biden wrote in a tweet.

Congratulations to Prime Minister Liz Truss.

I look forward to deepening the special relationship between our countries and working in close cooperation on global challenges, including continued support for Ukraine as it defends itself against Russian aggression.

— President Biden (@POTUS) September 6, 2022

Truss, previously the U.K.'s foreign minister, beat rival Rishi Sunak, the country's former finance minister, to win the leadership race. 

White House press secretary Karine Jean-Pierre said that Biden would speak to Truss this afternoon.

— Amanda Macias

Six NATO allies have yet to ratify Finland and Sweden's entry into the alliance

Six NATO member countries have yet to sign ratification protocols for Finland and Sweden to join the military alliance.

In May, both nations began the formal process of applying to NATO as Russia's war in Ukraine raged. All 30 members of the alliance have to ratify Sweden and Finland into the group.

Greece, Hungary, Portugal, Slovakia, Spain and Turkey are the six of the 30 allies yet to do so.

Last month, U.S. President Joe Biden signed ratification documents following a 95-1 Senate vote to bring Finland and Sweden into NATO.

— Amanda Macias

More than 1.7 million Ukrainian children have received mental health services as war marches on, U.N. says

The U.N. agency dedicated to observing the welfare of children said that it has administered mental health and psychosocial support services to more than 1.7 million children since Russia's war started earlier this year.

The United Nations Children's Fund, or UNICEF, said it's also working with the Ukrainian government on additional ways to support Ukrainian children.

UNICEF Executive Director Catherine Russell wrote in a statement that life for Ukrainian children has been "dramatically compromised" during two years of the Covid-19 pandemic and Russia's war.

"Their physical and mental health is under enormous strain," Russell wrote.

— Amanda Macias

IAEA details damage from shelling, poor work conditions at Zaporizhzhia nuclear site in new report

The International Atomic Energy Agency, or IAEA, released a report on its findings from a recent mission to the Zaporizhzhia nuclear power plant.

In the 52-page report, IAEA investigators warned that while ongoing shelling "has not yet triggered a nuclear emergency, it continues to represent a constant threat to nuclear safety and security."

"The IAEA recommends that shelling on site and in its vicinity should be stopped immediately to avoid any further damages to the plant and associated facilities, for the safety of the operating staff and to maintain the physical integrity to support safe and secure operation," wrote IAEA Director General Rafael Grossi.

The Ukrainian employees working at the site under Russian control were "under unbelievable pressure" and "morale and the emotional state of staff were very low," according to IAEA investigators.

Investigators described significant damage to buildings at the Zaporizhzhia nuclear power plant and confirmed that Russian military vehicles and equipment were seen stored at the site.

— Amanda Macias

U.S. Defense Secretary Austin heads to Germany to meet with allies on Ukraine

U.S. Defense Secretary Lloyd Austin will travel to Germany this week to host a meeting of the Ukraine Defense Contact Group.

The group, a coalition of nearly 40 countries supporting Ukraine's military needs, has met four times previously. The group will discuss additional ways to provide security assistance for Ukraine as Russia's war enters its seventh month.

Following the meeting at Ramstein Air Base in Germany, Austin will travel to the Czech Republic, a fellow NATO member state.

— Amanda Macias

Pentagon unable to share pace of flights carrying U.S. arms to Ukraine

The Pentagon said it was unable to provide an update on the number of flights that have transported U.S. military aid to Ukraine.

"I can tell you that the security assistance the U.S. is providing to Ukraine is enabling critical success on the battlefield against Russia's invading force," a Pentagon spokesman wrote in a statement. The spokesman referred the question on the pace and number of flights to the U.S. Transportation Command.

"We are actively working to facilitate the deliveries of security assistance from our allies and partners," the spokesman added.

The U.S. has committed about $12.9 billion in military assistance since Russia invaded Ukraine.

— Amanda Macias

The Kremlin announces sanctions on Sean Penn, Ben Stiller and U.S. senators

Moscow imposed personal sanctions on American celebrities Sean Penn and Ben Stiller, along with 23 other U.S. cultural figures and several U.S. senators.

"In response to the ever-expanding personal sanctions by the Biden Administration against Russian citizens, a group of persons from members of the U.S. Congress, high-ranking officials, representatives of business and expert communities, as well as cultural figures (25 people), are banned from entry into the Russian Federation on a permanent basis," the Russian Foreign Ministry wrote, according to an NBC News translation.

Penn and Stiller have been outspoken critics of Russia's war and have both visited Ukraine since the Kremlin's military campaign began nearly seven months ago.

U.S. Sens. Mark Kelly, Rick Scott and Kyrsten Sinema were also sanctioned.

— Amanda Macias

Russia is purchasing rockets and artillery from North Korea, U.S. Defense official says

Russia is buying millions of rockets and artillery shells from North Korea, a senior U.S. Defense official confirmed to NBC News.

"This purchase indicates that the Russian military continues to suffer from severe supply shortages in Ukraine, due in part to export controls and sanctions," the official told NBC News, confirming a New York Times report.

"We expect Russia could try to purchase additional North Korean military equipment going forward," the official added.

Last week, the Biden administration confirmed that Moscow purchased drones from Iran to use on the battlefield in Ukraine.

— Amanda Macias

Zelenskyy rings the NYSE opening bell and invites companies to invest in Ukraine

Ukrainian President Volodymyr Zelenskyy virtually rang the opening bell of the New York Stock Exchange in a bid to promote foreign investment in rebuilding Ukraine.

"We are rebuilding our economy. We are giving you and your companies the opportunity to work together with us," Zelenskyy said in brief remarks that he delivered in English, without a translator.

"Ukraine is a story of a future victory and a chance for you to invest now in projects worth of hundreds of billions of dollars, to share the victory with us," he said.

The European Union has signaled that it will provide hundreds of billions of dollars to help rebuild Ukraine, large portions of which have been flattened by Russian artillery barrages.

Zelenskyy spoke as the Ukrainian military mounted a massive counterattack aimed at driving Russian forces out of the province of Kherson.

-- Christina Wilkie

UN says at least 5,718 killed in Ukraine since start of war

The United Nations has confirmed 5,718 civilian deaths and 8,199 injuries in Ukraine since Russia invaded its ex-Soviet neighbor on Feb. 24.

The Office of the U.N. High Commissioner for Human Rights said the death toll in Ukraine is likely higher, because the armed conflict can delay fatality reports.

The international organization said most of the civilian casualties recorded were caused by the use of explosive weapons with a wide impact area, including shelling from heavy artillery and multiple launch rocket systems, as well as missiles and airstrikes.

— Amanda Macias

Ukraine and Russia accuse eachother of attacks around nuclear plant ahead of UN report

Russia and Ukraine have once again accused eachother of attacks on and around the Zaporizhzhia nuclear power plant on Tuesday, ahead of the publication of the UN nuclear watchdog's findings following its inspection of the facility.

Dmytro Orlov, the mayor of Enerhodar (which is located 5 kilometers east of the nuclear plant) said in a Telegram post Tuesday a powerful explosion had been reported in the town around midday today with power and water supplies coming to a halt.

Meanwhile, Russia's defense ministry claimed that Kyiv was carrying out " provocations" at the facility which it said were "aimed at creating a possible technological disaster."

It claimed Ukraine had launched 15 artillery attacks against Enerhodar and the nuclear power plant in the last 24 hours and had launched 20 shells against the locations, three of which it said were directed toward the the nuclear power plant, which it said had sustained some damage although radiation levels remained normal.

CNBC was unable to verify the information presented in the reports.

Ukraine and Russia have long accused eachother of shelling in and around the nuclear power plant, which was occupied by Russian forces early on in the conflict. Until last week, however, no independent inspection of the plant had taken place since the war started.

Today, the International Atomic Energy Agency, the UN's nuclear watchdog, is due to publish its findings following an inspection of the plant last week.

— Holly Ellyatt

Why has Russia halted gas supplies via Europe's main pipeline?

Russia's state-owned energy giant Gazprom has indefinitely suspended gas flows to Europe via a major pipeline, stoking fears some parts of the continent may need to ration energy through the winter.

However, while Gazprom cited an oil leak for the shutdown of the Nord Stream 1 pipeline, the Kremlin has since said that the resumption of gas supplies to Europe is dependent on Europe lifting its punitive economic measures.

"Problems in pumping arose because of the sanctions imposed against our country and against a number of companies by Western states, including Germany and the U.K.," Kremlin spokesman Dmitry Peskov told reporters on Monday, according to Russian state news agency Interfax.

Asked whether pumping gas via Nord Stream 1 was completely dependent on the sanctions and that supplies would resume if these were lifted, Peskov replied, "Of course ... It is precisely these sanctions that the Western states have introduced that have brought the situation to what we see now."

EU lawmakers accuse Russia of weaponizing energy supplies in a bid to sow uncertainty across the 27-nation bloc and boost energy prices.

— Sam Meredith

Uniper CEO says the worst is still to come after Russia halts gas flows to Europe

The chief executive of German gas giant Uniper has delivered a bleak assessment of Europe's deepening energy crisis, warning that the worst is still to come.

"I have said this a number of times now over this year and I'm educating also policymakers. Look, the worst is still to come," Uniper CEO Klaus-Dieter Maubach told CNBC's Hadley Gamble at Gastech 2022 in Milan, Italy.

"What we see on the wholesale market is 20 times the price that we have seen two years ago — 20 times. That is why I think we need to have really an open discussion with everyone taking responsibility on how to fix that," he added.

Read the full story here.

— Sam Meredith

Ukraine claims it has killed 50,000 Russian troops

Ukraine's armed forces claimed 50,150 Russian troops have been killed in the conflict in the country since the start of the war in February.

Ukraine also claimed, in its latest Facebook update, that it had destroyed 2,077 Russian tanks, almost 4,500 armored personnel vehicles, 1,179 artillery systems, 236 aircraft and 15 warships, among other losses.

The numbers should be read with some caution. CNBC was unable to independently confirm the data.

Moscow has released very few numbers regarding its personnel losses in Ukraine, with the data likely to prove unpopular with the Russia public.

— Holly Ellyatt

UN inspectors to release findings on nuclear power plant inspection

The International Atomic Energy Agency (IAEA) will release a report on Tuesday on its findings from the mission to the Zaporizhzhia nuclear power plant in the south of the country. The report will cover the nuclear safety, security and safeguards situation in Ukraine, the IAEA said in a statement.

IAEA inspectors inspected the Russian-occupied plant last week, with two of them staying on at the facility to maintain a presence at the site, which has found itself at the center of fighting in southern Ukraine. Russia and Ukraine have accused each other of shelling the plant and endangering its stability.

IAEA director-general Rafael Mariano Grossi will also brief the United Nations Security Council about the mission to the plant on Tuesday.

Ukraine informed the IAEA, a U.N. nuclear watchdog, on Monday that a backup power line between the nuclear power plant and a nearby thermal power station was deliberately disconnected today in order to extinguish a fire, but the line itself was not damaged. The plant continues to receive the electricity it needs for safety from its sole operating reactor.

— Holly Ellyatt

Russia may be running out of aerial drones in Kherson

Russian troops fighting in the Kherson area of Ukraine appear to be struggling to maintain their supply of unmanned aerial vehicles, the British Ministry of Defence said on Tuesday.

"The limited availability of reconnaissance UAVs is likely degrading commanders' tactical situational awareness and increasingly hampering Russian operations," the ministry said in a Twitter post.

Moscow military doctrine increasingly depends on UAVs to spot targets for Russian artillery, the U.K. ministry said.

CNBC is unable to confirm reports out of Kherson, where Ukraine launched a counteroffensive last week. Russia's ministry of defense did not immediately respond to a request for comment.

Ukraine reported shooting down three Russian tactical UAVs in a single day on Aug. 21. The British ministry cited a report in the Odesa Journal which claimed that Russian troops made 27 UAV sorties on Monday, down from an average of 50 a day in the month of August.

A sortie is typically defined as a single mission by a single aircraft. UAVs can be shot down or jammed electronically so that their operators lose control of them.

"In the face of combat losses, it is likely that Russia is struggling to maintain stocks of UAVs, exacerbated by component shortages resulting from international sanctions," the British Defence Ministry said.

— Ted Kemp

Gazprom says Siemens Energy has to repair turbine before gas supplies resume

A top Gazprom official has said that natural gas supplies to Europe via the Nord Stream 1 gas pipeline will not resume until Siemens Energy repairs faulty equipment.

When asked when supplies might resume, Gazprom's deputy CEO Vitaly Markelov told Reuters on Tuesday that "you should ask Siemens. They have to repair equipment first," he told Reuters on the sidelines of the Eastern Economic Forum in the far eastern Russian city of Vladivostok.

Gazprom halted all flows through the pipeline on Friday after it said it had detected an oil leak in a turbine engine at the Portovaya compressor station and said it would cut off supplies until the issue was fixed.

Siemens Energy, which has supplied and serviced Nord Stream 1 turbines, responded by saying that the leak was not a reason to stop gas flows.

"As the manufacturer of the turbines, we can only state that such a finding is not a technical reason for stopping operation," it said in a statement, adding that such leakages do not usually affect the operation of a turbine and can be sealed on site.

Such repairs were routine procedures, Siemens Energy said, adding that in the past, "the occurrence of this type of leakage has not resulted in a shutdown of operations."

"Irrespective of this, we have already pointed out several times that there are enough additional turbines available at the Portovaya compressor station for Nord Stream 1 to operate," it added.

Siemens Energy said it was "currently not contracted for maintenance work, but is standing by."

— Holly Ellyatt

Russian energy minister says price cap will lead to shipping more Russian oil to Asia

Russian energy minister Nikolai Shulginov said the country will ship more oil to Asia in response to price caps on its oil exports, Reuters reported.

"Any actions to impose a price cap will lead to deficit on (initiating countries') own markets and will increase price volatility," he told reporters at the Eastern Economic Forum in Vladivostok, according to Reuters.

Last week, the G-7 economic powers agreed to cap the price of Russian crude to punish Moscow for its unprovoked invasion of Ukraine. Before the invasion, Russia exported approximately half of its crude and petroleum product exports to Europe, according to the International Energy Agency.

— Natalie Tham

Zelenskyy vows 'response' for attack on hometown, applauds destruction of Russian missile warehouse

Ukrainian President Volodymyr Zelenskyy commended Ukrainian fighters who destroyed a Russian missile warehouse and vowed action following an attack on his hometown.

"I especially want to thank the fighters of one of our rocket artillery brigades who with their accurate fire destroyed the very Russian warehouse from which the occupiers got S-300 missiles to bomb Kharkiv," Zelenskyy said in a statement posted to his official Telegram and translated by NBC.

Zelenskyy added that the "occupiers will definitely get a response" for Monday's missile attack on his hometown of Kryvyi Rih, and the continued shelling across other territories.

— Samantha Subin

Macron urges French to cut energy use 10% to avoid rationing

French President Emmanuel Macron on Monday called for a 10% reduction in France's energy use in the coming weeks to avoid rationing and cuts amid tensions with supplier Russia, according to the Associated Press.

Energy rationing plans are being prepared “in case” they’re needed, and that “cuts will happen as a last resort," he said at a news conference.

“The best energy is that which we don’t consume,” Macron said, urging French businesses and households to save energy, including by turning down heating and air conditioning, the AP said.

Speaking after a videoconference Monday with German Chancellor Olaf Scholz, Macron announced a plan to boost gas supplies to Germany from France to make up for a drop in Russian gas supplies from the east.

Germany will continue supplying power to France to make up for shortages caused by maintenance on many French nuclear reactors.

—AP

Boris Johnson says Ukraine will defeat Russia in outgoing call

Boris Johnson told President Volodymyr Zelenskyy that Ukraine can and will defeat Russia in his final call as U.K. prime minister.

Johnson, who on Monday was replaced as leader of the Conservative Party by Liz Truss, pledged to maintain a close friendship with Zelenskyy even as he leaves office.

"The Prime Minister told President Zelenskyy it had been a privilege to work with him and support him, and the leaders agreed to stay in close touch as friends," a Downing Street spokesperson said.

— Karen Gilchrist