 -- Egyptian authorities said a bomb is the most plausible reason for last weekend's deadly Russian jet crash after taking off from Egypt's Sharm el Sheikh Airport, as Russia decided to halt all flights to Egypt.

A government official in Sharm el Sheikh told ABC News Egyptian authorities can no longer dismiss the possibility that a bomb was placed on the plane and, in their mind, it is the most "plausible" scenario, adding that a technical problem is now at the bottom of their list of possible scenarios.

Meanwhile, Russian President Vladimir Putin today agreed to suspend all Russian flights to Egypt, a Putin spokesman confirmed, according to Interfax.

The Russian news agency also quoted a Russian official’s suggestion that all Russian flights to Egypt, the plane's origin, should be stopped until the cause of the plane crash is determined.

“While we are still have not determined the true causes of what happened, I think it would be advisable to halt all flights by Russian aviation to Egypt. That is, above all, tourist flights,” Aleksandr Bortnikov, director of the Federal Security Service of the Russian Federation, said, according to Interfax.

Putin supported the Russian intelligence chief’s recommendation, his spokesman said.

British Foreign Secretary Philip Hammond said late Wednesday that while the investigation is ongoing, there was a "significant possibility" the crash was caused by a bomb, and Britain was suspending flights to and from the Sinai resort city indefinitely.

Asked today whether Obama was considering suspending U.S. flights in the area like Russia and the U.K., White House Press Secretary Josh Earnest said, “at this point, no.”

Earnest said the safety precautions announced today by the Department of Homeland Security are what "we believe are necessary."

Earnest added, “while we can’t rule anything in or out, we have to consider the possibility that-- of potential terrorist involvement here.”

The cause of Saturday's crash in the Egyptian desert remains undetermined and the black boxes are still being analyzed.