U.S. is confident that a terrorist bomb brought down the Russian passenger jet.

The U.S. appears to be increasingly confident that a terrorist bomb brought down the Russian passenger jet that broke apart over Egypt.

The growing belief was indicated by several senior U.S. officials in the intelligence, military and national security community who spoke to CNN on Saturday.

One official said it was "99.9% certain," another said it was "likely."

The remarks are stronger than those made by President Barack Obama on Thursday when he said there was "a possibility" a bomb was on Metrojet Flight 9268, which disintegrated over the Sinai Peninsula on October 31, killing all 224 people aboard.

The view also contrasts with the cautious stance taken by Egyptian officials, who are in charge of the main investigation into the air crash and insist that no conclusion has been reached yet.