One of the photos from the Facebook page of USS Decatur showing a crew member on the ship's deck.
A San Diego-based destroyer is one of two U.S. ships currently positioned to respond to any missile threats from North Korean, according to the Pentagon.
USS Decatur was heading back home to San Diego when it was re-missioned to be on alert in the western Pacific, NBC News reports.
The White House and the State Department said they were taking seriously an almost daily string of threats from North Korea toward the U.S. and South Korea, ratcheted up a notch Tuesday when the North said it would revive its long-dormant reactor and ramp up production of nuclear weapons material.
Retired Admiral Tim LaFleur once commanded all Naval Surface Ships and said the North Korean threat to us in San Diego is very low, but they do have long range missiles that could reach parts of the U.S.
"We're showing them that we're committed were making sure that we do stuff so that were not in a defensive position - we're prepared to respond to them," he said.
LaFleur says North Korea has shown no signs of moving their own forces, which is a good indicator they're not planning an attack that would start a war.
USS McCain has joined USS Decatur in the missile defense mission Pentagon Press Secretary George Little said Tuesday adding that neither ship is involved in the ongoing U.S.-South Korea exercise Foal Eagle.
Another destroyer, the USS Fitzgerald, is also in the region to respond, if necessary, according to NBC News.