Iran slammed the United States on Saturday for what it called an "inhumane" decision to bar its foreign minister, who was attending the U.N. summit meetings in New York, from visiting a hospitalized Iranian diplomat in the city.
U.S. authorities were not allowing Iranian Foreign Minister Mohammad Javad Zarif to visit U.N. ambassador Majid Takht Ravanchi, who was undergoing cancer treatment in a New York hospital. In July, the U.S. restricted Zarif's movement to just six blocks in New York.
The U.S. State Department said it would allow the hospital visit request only if Iran released one of several U.S. citizens it currently has "wrongfully detained."
The official IRNA news agency quoted Deputy Foreign Minister Abbas Araghchi as saying the U.S. had taken humanitarian issues "hostage" for political causes.
Late on Saturday, Zarif tweeted that he had communicated with Ravanchi by video call.
"Thanks to technology, I was able to see and talk to my friend of 40 years and our UN ambassador Ravanchi, who is in hospital here in New York only a few blocks away," he said.
The spat comes amid heightened tension between Tehran and Washington following U.S. President Donald Trump's decision over a year ago to unilaterally pull out of a nuclear deal with Iran. The U.S. has imposed sanctions that have kept Iran from selling its oil abroad and have crippled its economy. Iran has since begun breaking terms of the deal.
The tensions have included seizures of oil tankers at sea. On Friday, Iran released a British-flagged oil tanker it had seized in July as it passed through the Strait of Hormuz, the narrow mouth of the Persian Gulf through which 20% of all oil passes.
The ship, the Stena Impero, set sail from Iran on Friday morning, arriving at an anchorage outside Dubai's Port Rashid in the United Arab Emirates just before midnight. It docked on Saturday afternoon.
Erik Hanell, president and CEO of Swedish-based Stena Bulk, which owns the tanker, said that "considering the circumstances of the past 10 weeks, the vessel is in good condition," which he said was testament to the professionalism of the crew.
The crew would go on shore leave while the Stena Impero, with a new crew on board, would remain in Dubai for checks before re-entering service, Hanell said in an emailed statement.
The Stena Impero's seizure came after authorities in Gibraltar, a British overseas territory, seized an Iranian supertanker carrying $130 million in crude oil on suspicion it was breaking European Union sanctions by taking the oil to Syria. Gibraltar later released the tanker, then called the Grace 1, after it said Iran promised the ship wouldn't go to Syria.
Renamed the Adrian Darya 1, the ship later sat off the Syrian coast, angering Britain. Iran hasn't said who purchased its 2.1 million barrels of crude oil.
Britain responded to Iran's release of the Stena Impero on Friday by accusing Tehran of trying to disrupt freedom of navigation.
The Persian Gulf tensions have also seen a series of attacks across the Middle East that the U.S. blames on Iran. They reached their height on Sept. 14, with a missile and drone attack on the world's largest oil processor in Saudi Arabia and an oil field, which caused oil prices to spike by the biggest percentage since the 1991 Gulf War. While Yemen's Iranian-allied Houthi rebels claimed the assault, Saudi Arabia says it was "unquestionably sponsored by Iran."
Iran denies being responsible and has warned that any retaliatory attack targeting it will result in an "all-out war."
Elena Becatoros contributed.