US President Donald Trump crossed “a very dangerous red line” after Iran’s supreme leader Ali Khamenei was killed in US-Israeli strikes, an Iranian official told CNN. Follow for live updates.

Iran has vowed revenge after the killing of its supreme leader. It traded strikes with Israel on Sunday as part of a widening war prompted by a surprise U.S. and Israeli bombardment a day earlier.

Iranian state media have confirmed the death of Supreme Leader Ayatollah Ali Khamenei in a major attack by Israel and the United States.

At least one gathering of senior officials and military leaders was hit, but it was not immediately clear whether the effort to kill them had succeeded.

The United States took military action in Iran, President Donald Trump announced on Feb. 28, following repeated threats from ...