The US Navy has sent a second ship to the South China Sea to help in the desperate search for a missing Malaysian jet, officials said Monday.
The naval destroyer USS Kidd has joined another American destroyer, the USS Pinckney, as Malaysian authorities announced they were doubling the size of the search area for the airliner that vanished without a trace Saturday with 239 on board.
"We are continuing to assist the Malaysian government in search and rescue operations in conjunction with the disappearance of Flight 370," Pentagon spokesman Colonel Steven Warren told reporters.
The two US naval ships are equipped with MH-60 Sea Hawk helicopters, which are equipped with infrared cameras for night-time search operations, he said.
On Sunday, the Pinckney spotted debris in the water but officers determined it was not wreckage from the missing airliner and merely "an old shipping crate," he said.
A P-3C Orion surveillance aircraft was already in place and was conducting nine-hour flights from a base in Subang Jaya, Malaysia.
An oiler vessel also was deployed to provide logistics support, Warren said.
The US government over the weekend sent a team of investigators and experts from the FBI and the National Transportation Safety Board to help with the probe into the missing plane.
US officials say it remains unclear if there was any terror link behind the disappearance of Malaysia Airlines Flight 370, which had taken off from Kuala Lumpur en route to Beijing.