Iran's armed forces on Wednesday warned Gulf countries against assisting the US military, saying it would be tantamount to joining American military operations.

"We wish to warn that any assistance or facilitation provided to the aggressor US military amounts to participation in the US military operation," armed forces chief of staff Ali Abdollahi said, according to Iran's Mehr news agency.

War between Iran and the United States broke out on 28 February after US-Israeli attacks on the Islamic republic, which retaliated with missile and drone strikes including on US bases across the region.

"It seems unlikely that such a large number of military aircraft, particularly refuelling aircraft could be present at regional bases without knowledge of host countries," said Abdollahi.

"The countries bordering the Persian Gulf, which have issued various statements saying they would not allow the United States to use their territory against Iran, should know that we are fully aware of the situation."

The warning comes as the USS George Washington aircraft carrier is being redeployed to the Middle East to relieve the USS Abraham Lincoln following reports of deteriorating living conditions for its crew.