WASHINGTON — President Obama said Thursday evening that there was “a possibility” that a terrorist bomb was responsible for the destruction of a Russian passenger plane that broke apart last Saturday over the Sinai Peninsula in Egypt.

Mr. Obama said in a radio interview that there may have been a bomb on the plane, but he did not go as far as his counterparts in Britain, who have suggested that the destruction of the plane, and the death of all on board, was most likely the result of a terrorist explosion.

“I don’t think we know yet,” Mr. Obama told the Seattle radio station KIRO during an interview broadcast Thursday afternoon. “Whenever you’ve got a plane crash, first of all you’ve got the tragedy, you’ve got making sure there’s an investigation on site. I think there is a possibility that there was a bomb on board. And we are taking that very seriously.”

“We are going to spend a lot of time making sure our own investigators and our own intelligence community figures out exactly what’s going on before we make any definitive pronouncements,” Mr. Obama added. “But it is certainly possible that there was a bomb on board.”