WH: Not enough info on missing jet

White House Press Secretary Jay Carney said Monday that U.S. officials "do not have enough information to comment on the cause" of the Malayasia Airlines flight that has been missing since Friday evening.

U.S. officials have traveled to Vietnam, where the Malayasia Air flight was last detected by air traffic controllers, to assist in the search for remnants of the plane, which was carrying 239 passengers.

Carney said Monday that "the United States government is in communication…with international partners to provide any appropriate assistance in the investigation. 

"Officials from the National Transportation Safety Board and Federal Aviation Administration are en route to the region to provide any necessary assistance," the White House's chief spokesman said.

"Also, as I think you probably know, the [Defense Department] said over the weekend that the 7th Fleet has sent assets to search efforts, including the USS Pinckney, an Arleigh Burke-class guided missile destroyer, which is now in the vicinity and has two MH-60R helicopters equipped for search efforts on board," Carney continued. "Additionally a P-C3 Orion aircraft from our base in Okinawa is now in the region, and that's long-range search, radar and communications capabilities. So we're providing assistance."

But Carney said it would be awhile before officials from any of the countries that are involved in the search for the missing Malayasia Air flight would be confident enough to make assumptions about why the jet disappeared.

"Obviously, the Malaysians have the lead in this investigation, but we do not have enough information at this time to comment on the cause," he said. "First and foremost, our thoughts and prayers are with the families affected by this tragic incident. And as you know, the State Department has said that there were three American citizens onboard -- and, of course, many more from around the world, especially China, Taiwan and Malaysia."

The Malaysia Air flight, which was a Boeing 777, was being operated from Kuala Lumpur to Beijing, China when it lost contact with air traffic controllers about an hour into its flight.

Vietnamese officials report that the airplane did not send any distress signals, which are common when flights experience mechanical problems.

Relatives of passengers who are known to have been on the flight have expressed anger at Malayasia Air for a lack of information about the whereabouts of the airplane, but aviation industry officials have said that is difficult to provide updates about a flight that has not been found in three days.