A picture taken from Animation film "Battle of Persian Gulf II" depicts an armed confrontation between Iran's Revolutionary Guards and the U.S.Navy. (Xinhua/Reuters Photo)

TEHRAN, March 8 (Xinhua) -- A navy commander of Iran's Islamic Revolution Guards Corps (IRGC) said Wednesday that an American warship has recently sailed close to the IRGC's vessels near Iranian territorial waters in Persian Gulf which is "unprofessional," Press TV reported.

The American ship was sailing as a part of a naval fleet which also comprised British vessels, Mehdi Hashemi said, adding that it steered out of the international naval transit in the Persian Gulf, coming within 550 meters (0.3 nautical miles) of IRGC vessels.

On Monday, an unnamed U.S. Navy official said that a U.S. ship was forced to change course and move out of the way of Iranian fast boats while moving through the Strait of Hormuz on Saturday.

The Iranian boats tried to get between the U.S. and other ships, coming within about 600 yards of the USNS Invincible, a tracking ship, the official said, adding that the U.S. ship was travelling north through the strait into the Persian Gulf.

The IRGC commander, however, denied the allegations, saying that they are "lies."

He added that the presence of American and British vessels in the Persian Gulf "endangers the security of this strategic region, which provides a huge portion of the world's energy."