Indonesia has requested help from the United States to search for a missing AirAsia jetliner, U.S. officials said Monday, amid fears the aircraft crashed into the sea.

The State Department also confirmed that no Americans were on Flight QZ8501, which disappeared on Sunday over the Java Sea with 162 people on board.

"Our embassy in Jakarta is in close contact with Indonesian officials, and today, we received a request for assistance locating the airplane," said Jeffrey Rathke, a State Department spokesman.

"We are reviewing that request to find out how best we can meet Indonesia's request for assistance."

He noted it would take "a little bit of time" to evaluate the request, without detailing what kind of aid — military or otherwise — the United States might provide.

Pentagon spokesman Rear Admiral John Kirby said the aid could include "some air, surface and sub-surface detection capabilities."

"We stand ready to assist in any way possible," he added.

Dozens of planes and ships were searching for the missing plane, which lost contact en route from Surabaya in Indonesia's east Java to Singapore after the crew requested a change of flight plan due to stormy weather, in the third crisis for a Malaysian carrier this year.

Australia, Malaysia and Singapore have joined the Indonesia-led search as anguished relatives awaited news of their loved ones.