U.S. sailors made 'navigational error' into Iranian waters

US Secretary of Defense Ashton Carter says the US sailors who trespassed into Iranian waters had made a "navigational error".

"It does appear - the information that they have given us and through their commanders - that they did stray accidentally into Iranian waters due to a navigation error", Carter said in an interview in Miami with Fusion network.

"The decision to release the sailors was taken after it was confirmed that they had not meant to enter Iranian waters", IRNA, Iran's semi-official news agency, quoted a Revolutionary Guards statement as saying.

Ten U.S. sailors, nine men and one women, were detained Tuesday on the Farsi island in the Gulf by Iran's military which seized two U.S. Navy boats drifting into Iranian waters, U.S. media reported.

"We will find out more what combination of factors led to that navigational error, but they were clearly out of the position that they meant to be in", Carter said.

The boats, known as riverine command boats, were en route from Kuwait to Bahrain. It may be that they were trying to sort it out at the time they encountered Iranian boats.... Farsi Island is a naval base for Iran's naval component of the Revolutionary Guard Corps and is considered extremely sensitive.

One US official, speaking on condition of anonymity, said it was clear the boats did not run out of fuel. It's not believed the engine trouble was the cause of going off course. Navy officials said the 10 were undergoing what the military calls "reintegration", a series of interviews and physical and mental health examinations to ease their return to duty. The Iranians did not interfere, the defense official said.

With the administration on the defensive over the video, State Department spokesman John Kirby told CNN's Jake Tapper on "The Lead" that the images were "hard to look at" but urged critics to concentrate on the fact that the sailors were returned quickly.

"Obviously I don t like to see our people detained by a foreign military", Carter said.

On Friday, White House press secretary Josh Earnest told reporters that the administration was not embarrassed by the images of the sailors released by Iran state media.

"For the most part, the gear we deployed with was largely there when we got the boats back", he said.