SINGAPORE - US warship USS John S. McCain suffered a "steering failure" as the warship was beginning its approach into the Singapore Strait, causing it to collide with a commercial tanker on Monday (Aug 21), a US Navy official told CNN.

The official said it was unclear why the crew could not utilise the ship's backup steering systems to maintain control of the ship.

Earlier, another US Navy official told CNN there were indications the destroyer experienced a loss of steering right before the collision, but that steering had been regained after the collision.

It is not clear from the CNN report what is meant by "steering failure".

While there was no indication the collision was intentional nor any evidence that the ship was the target of a cyberattack, investigators would not discount these possibilities, Chief of Naval Operations John Richardson told reporters.

"We are taking a look at all (options) as we did with the (USS) Fitzgerald as well," he said.

The incident has prompted the US Navy to order a fleet-wide investigation and plans for temporary halts in operations to focus on safety.

The review will take place over a week in a series of 24-hour periods, during which on-board actions as well as leadership and operational procedures will be examined, according to CNN.

Speaking at the Osan Air Base in South Korea, Admiral Harry Harris, commander of the US forces in the Pacific, said that the operational pause is "important", but added the pause "would not have an effect" on the US' ability "to defend our nation and our allies".

The USS John S. McCain and the tanker Alnic MC collided while the guided-missile vessel was nearing Singapore for a routine port call.

The collision tore a hole in the warship's port side at the waterline, flooding compartments that included a crew sleeping area.