WASHINGTON - US Defense Secretary Ash Carter confirmed Thursday that "a navigational error" had led to the incident in which 10 US sailors were detained briefly by Iran in the Gulf.

"There was a navigational error of some kind," Carter told a news conference held at the US Central Command Headquarters in the Macdill Air Force Base in Florida.

"All the contributing factors to that, we don't know yet and we're still talking to those folks and we'll find out more what combination of factors led to that navigational error," said the Pentagon chief.

He added that the Pentagon is still talking to the sailors to learn about "exactly what happened."

Earlier in an interview with a local media outlet in Miami, Carter admitted that the US soldiers "did stray accidentally into Iranian waters due to a navigation error."

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

But the sailors were released Wednesday after US Secretary of State John Kerry had held several phone talks with his Iranian counterpart to demand for their immediate release.

Kerry said Wednesday that he thanked the Iranians for their cooperation and quick response on the matter, adding that "this is a testament to the critical role diplomacy plays in keeping our country safe."