While the U.S. insists it is not involved in strikes on Iran, American officials have confirmed military forces have been helping to intercept Iranian missiles fired at Israel.

The three-day gathering in the mountain town of Kananaskis marks the return to the international diplomatic calendar for Trump, who has stunned allies by defying norms and slapping sweeping tariffs on friend and foe alike.

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.

President Donald Trump rejected an Israeli plan in recent days to kill Iran's Supreme Leader Ayatollah Ali Khamenei, two U.S. officials told ABC News. The officials stated that Israel shared with the United States that they had a window to kill Iran's leader but the president was not on board with the plan.

The conflict, the most intense fighting between the two countries in decades, has been met in the United States with feelings of “frustration and helplessness,” as well as heartbreak.

Israel's strikes on Iran are unprecedented, placing the Middle East on the brink of full-scale war between nation-states. Here is the list of all the regime's top military, intelligence and security leaders that have been killed,

Israel has said it launched Operation Rising Lion to deal a blow to Iran’s nuclear ambitions. Prime Minister Benjamin Netanyahu has claimed that the strikes are essential to ‘roll back the Iranian threat to Israel’s very survival’ and that Tehran could build a nuclear weapon within a few months.

Israel on Sunday hit targets in Tehran, including the Defense Ministry and sites it claims are tied to Iran's nuclear program.