Donald Trump has announced that the US has bombed three nuclear sites in Iran, directly joining Israel’s effort to destroy the country’s nuclear program in a risky gambit to weaken a longtime foe amid Tehran’s threat of reprisals that could spark a wider regional conflict.

"Our objective was the destruction of Iran’s nuclear enrichment capacity and a stop to the nuclear threat posed by the world’s number one state sponsor of terror," Trump said in a speech from the White House, adding: "Tonight, I can report to the world that the strikes were a spectacular military success. Iran’s key nuclear enrichment facilities have been completely and totally obliterated."