The U.S. president faces pushback over the risk of U.S. involvement in the escalating conflict between Israel and Iran.

Hundreds of civilians, mostly in Iran, have been killed by dueling airstrikes despite international pleas for de-escalation.

President Trump rejected an Israeli plan in recent days to kill Iran's Supreme Leader Ayatollah Ali Khamenei, a senior U.S. official told USA TODAY.

The deadly conflict between Israel and Iran has entered a fourth day, with both sides firing waves of missiles. Follow for live updates.

BEIRUT — Iran and Israel traded air raids and ballistic missile barrages overnight and into the evening Sunday, with neither side showing any inclination to back down from an escalating grudge match between the two longtime enemies.

The president had opposed Israeli action against Iran but came to believe that Israel had reason to act and that the U.S. would have to lend some support.

Iran has vowed to retaliate against the U.S., too, while Trump has warned: “If we are attacked in any way, shape, or form by Iran, the full strength and might of the U.S. Armed Forces will come down on you at levels never seen before.” Here’s what to know about U.S. involvement so far.

The war between Israel and Iran is in its fourth day, with Israel striking at military sites and Iran's nuclear program and Iran firing missiles in retaliation

DUBAI — Israel unleashed airstrikes across Iran for a third day Sunday and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the country. Planned talks on Iran’s nuclear program, which could provide an offramp, were canceled.