The chief of the search effort for missing Indonesia AirAsia flight 8501, which vanished a day earlier, stated Monday that "the hypothesis is the plane is at the bottom of the sea."
Bambang Soelistyo, chief of Indonesia's Search and Rescue Agency (BASARNAS), spoke to reporters in Jakarta, adding that this is "the preliminary suspicion and it can develop based on the evaluation of the result of our search."
Military aircraft from Indonesia, Singapore and Malaysia are flying over the Java Sea searching for any wreckage from the Airbus 320.
Reports have come in from an Australian Orion aircraft of debris found about 1,100 kilometers from where the plane lost contact, but there is no indication yet if they are pieces of the missing plane.
The US Navy's 7th Fleet said in a statement it had not been asked to join the search.
"As we have in the past, the U.S. Navy assets in 7th Fleet stand ready to assist in any way that's helpful," said Lt. Lauren Cole, deputy public affairs officer for the fleet.
But American assistance could be en route soon. Soelistyo said Indonesia does not have the tools necessary for a submersible search, "so we will borrow from other countries which have offered. They are the U.K., France and U.S."
The relatively shallow Java Sea is one of the world's busiest waterways.
The jetliner departed Surabaya for Singapore's Changi airport early Sunday on what should have been a two-hour flight. But flight QZ8501 disappeared about halfway to Singapore.
The pilot had asked air traffic controllers for permission to ascend about 1,800 meters to nearly 11,600 meters (38,000 feet) to avoid stormy weather. An Indonesian transport ministry official said permission was denied because another plane was flying in the area.
After that, communication went silent. Controllers did not receive any distress call from the pilot. The last transmission from a crew member on the Airbus reportedly came at 6:12 a.m. local time on Sunday.
On board were 149 Indonesian passengers, including 16 children. The flight manifest also lists three South Koreans (one of them an infant), a Malaysian and a British man traveling with his two-year-old Singaporean daughter.
The flight crew was composed of two pilots, four flight attendants and one engineer - all Indonesian citizens except for the French first officer, according to AirAsia.
The captain in command is described as quite experienced with more than 20,000 flying hours -- roughly 6,000 of those hours with Indonesia AirAsia in the cockpit of the Airbus A320.
Relatives of passengers and crew were briefed Monday morning at Surabaya airport. They also met behind closed doors with AirAsia CEO Tony Fernandes, who is grappling with the budget airline group's first tragedy since it took to the skies in 1996.
"Until today we have never lost a life. But I think any airline CEO who says that he can guarantee that his airline is 100 percent safe is not accurate. There are so many factors," Fernandes said on Monday. "And right now we cannot speculate as to what was the cause of the accident."
Indonesia AirAsia, previously known as Air Wagon International which began flying in 1999, is 49 percent owned by Malaysia-based AirAsia. The low-cost AirAsia family of airlines serves more than 100 destinations in 22 countries.
AirAsia has become Airbus' largest customer for the A320 and ordered 100 more of the twin engine jet planes two years ago. The aircraft is usually configured to hold between 150 and 180 passengers and operates on short to medium-haul routes.