As the war continues into a third day, Trump, in a video message, says 'there will likely be more' US service members killed in the Iran conflict before it ends.

The war over Iran engulfed more of the Middle East and beyond on Monday as Lebanon's militant group Hezbollah responded to the killing of Iran's spiritual leader with its first attack on Israel in more than a year.

The interim leadership council of Iran has been formed following the death of Supreme Leader Ayatollah Ali Khamenei, Iranian state TV reported Sunday.

Follow NBC News' live coverage as the U.S. and Israel attack Iran, Tehran hits back across the Gulf and Hezbollah strikes from Lebanon while Iran chooses a new supreme leader after the killing of Ayatollah Ali Khamenei.

In the pre-dawn hours of Monday morning, Hezbollah opened a new front in the US-Israeli war against Iran when it launched “missiles and a swarm of drones” at a military base in northern Israel.

This attack marked Hezbollah's first action against Israel's northern regions since 2024, officially joining the conflict alongside Iran. The IDF announced that it precisely struck senior Hezbollah

Read the latest news on Hezbollah, the Lebanese group locked in a series of conflict with Israel. Get comprehensive coverage on Reuters.