Indonesia has asked the United States for help in locating the AirAsia jet that went missing on Sunday carrying 162 people, the U.S. State Department said on Monday.
"Today we received a request for assistance locating the airplane, and we are reviewing that request to find out how best we can meet Indonesia's request for assistance," State Department spokesman Jeff Rathke told a regular news briefing.
The Indonesia AirAsia plane, an Airbus A320-200, disappeared after its pilot failed to get permission to fly higher to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore on Sunday.
Flight QZ8501 did not issue a distress signal and disappeared over the Java Sea five minutes after requesting the change of course, which was refused because of heavy air traffic, officials said.
Indonesian Vice President Jusuf Kalla, visiting relatives of people on the flight in Surabaya, told reporters the search by 30 ships and 15 aircraft, about halfway between Surabaya and Singapore, was being hampered by bad weather.
Anger was growing among about 100 relatives at a crisis center at the airport in Indonesia's second-largest city.
"We only need clear information every hour on where they are going," said Franky Chandra, who has a sibling and three friends on the flight, referring to the search teams.
"We've been here for two days but the information is unclear. That's all we need."
Australia, Malaysia, Singapore and South Korea have sent ships and aircraft to join the search, and China offered to send planes and ships and any other help Indonesia needs.