Trump says U.S. has begun 'major combat operations in Iran'

"Our objective is to defend the American people by eliminating imminent threats from the Iranian regime," he said in the video, posted at 2:30 a.m. ET Saturday.

"It has always been the policy of the United States, in particular my administration, that this terrorist regime can never have a nuclear weapon. I’ll say it again, they can never have a nuclear weapon," he said.

Iranian state media reports explosions in two locations in central Tehran

 Explosions in two locations in central Tehran on Saturday morning local time.