President Joe Biden has condemned Iran's unprecedented air attack on Israel and convened a meeting of the G-7 leaders on Sunday to develop a coordinated response to the brazen assault.

His comments came as American forces joined efforts to down drones and missiles launched by Tehran.

Israel said it and its allies have intercepted the vast majority of more than 200 drones and missiles launched by Iran.

"Earlier today, Iran—and its proxies operating out of Yemen, Syria and Iraq—launched an unprecedented air attack against military facilities in Israel. I condemn these attacks in the strongest possible terms," Biden said after his call with Israeli Prime Minister Benjamin Netanyahu.

Biden said at his direction, to support the defence of Israel, the US military moved aircraft and ballistic missile defence destroyers to the region over the course of the past week.

“Thanks to these deployments and the extraordinary skill of our servicemembers, we helped Israel take down nearly all of the incoming drones and missiles,” he said.

“I've just spoken with Prime Minister Netanyahu to reaffirm America's ironclad commitment to the security of Israel," he said.

Israel demonstrated a remarkable capacity to defend against and defeat even unprecedented attacks – sending a clear message to its foes that they cannot effectively threaten the security of Israel, he said.

“Tomorrow, I will convene my fellow G7 leaders to coordinate a united diplomatic response to Iran's brazen attack.

"My team will engage with their counterparts across the region. And we will stay in close touch with Israel's leaders. And while we have not seen attacks on our forces or facilities today, we will remain vigilant to all threats and will not hesitate to take all necessary action to protect our people,” Biden said.