U.S. President Donald Trump sharply criticized Iran's supreme leader, Ali Khamanei, on Friday, dropped plans to lift sanctions on Iran and said he would consider bombing Iran again if Tehran is enriching uranium to worrisome levels.

Trump reacted sternly to Khamanei's first remarks after a 12-day conflict with Israel that ended when the United States launched bombing raids last weekend against Iranian nuclear sites.

Khamanei said Iran "slapped America in the face" by launching an attack against a major U.S. base in Qatar following the U.S. bombing raids. Khamanei also said Iran would never surrender.