"All of our soldiers are safe and only minimal damage was sustained at our military bases. Our great American forces are prepared for anything," he said in an address to the nation from the White House.

"Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world. No American or Iraqi lives were lost."

Trump announced the United States would be imposing "additional punishing sanctions" on Iran but made no mention of possible retaliation to Tuesday's missile attacks -- seen by experts as a measured first response by Iran to the killing of General Qasem Soleimani in an American drone strike.