The US, Canada and the UN have condemned the Iranian air attack on Israel, with President Joe Biden reaffirming America’s "ironclad commitment" to the Jewish nation and vowing to convene a meeting of the G-7 leaders on Sunday to develop a coordinated response to the brazen assault.

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

Biden said "We helped Israel take down nearly all" of them.

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

"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 on Saturday.

Iran's Islamic Revolution Guard Corps (IRGC) said the attack was aimed at "specific targets".

Iran had vowed to retaliate for a strike on its consulate in Syria on 1 April which killed seven IRGC officers, including a top commander. It accused Israel of carrying out that attack, but Israel neither confirmed nor denied it.

Netanyahu called a war cabinet meeting after the start of the Iranian attack, and later spoke to President Biden, who said he had reaffirmed "America's ironclad commitment to the security of Israel".

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 G-7 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.

In New York, UN Secretary-General, Antonio Guterres in a statement condemned the serious escalation represented by the large-scale attack launched on Israel by Iran. “I call for an immediate cessation of these hostilities,” he said.

“I am deeply alarmed about the very real danger of a devastating region-wide escalation. I urge all parties to exercise maximum restraint to avoid any action that could lead to major military confrontations on multiple fronts in the Middle East,” he said.

UN General Assembly Dennis Francis expressed deep concerns about the unfolding situation in the Middle East, involving the launch by Iran of drones and missiles against Israel.

“The Iranians have explained their action in the context of article 51 of the UN Charter, following the recent Israeli attack on the Iranian Embassy in Damascus. The Iranian response compounds the already tense and delicate peace and security situation in the Middle East,” he said and called upon all parties to exercise the utmost restraint to avoid further escalation of tension in the region.

This is a moment that calls for wise and prudent judgement, in which the risks and extended risks are very carefully considered, he said.

“I expect that the Iranian authorities will honour their word that by their action today, the matter can be deemed concluded. A vicious cycle of attack and counter-attack will lead to nowhere, but inevitably, to more death, suffering and misery. Dialogue and diplomacy are the only way to resolve any differences through peaceful means,” Francis said.

Canadian Prime Minister Justin Trudeau unequivocally condemned Iran’s airborne attacks against Israel.

“We stand with Israel. After supporting Hamas’ brutal October 7 attack, the Iranian regime’s latest actions will further destabilise the region and make lasting peace more difficult,” he said.

“These attacks demonstrate yet again the Iranian regime’s disregard for peace and stability in the region. We support Israel’s right to defend itself and its people from these attacks,” Trudeau said.

Meanwhile, US Defence Secretary Lloyd Austin said that American forces remain postured to protect its troops and partners in the region, provide further support for Israel’s defence, and enhance regional stability.

“We condemn these reckless and unprecedented attacks by Iran and its proxies, and we call on Iran to immediately halt any further attacks, including from its proxy forces, and to de-escalate tensions. We do not seek conflict with Iran, but we will not hesitate to act to protect our forces and support the defence of Israel,” he said.

Austin said he will continue to monitor the situation closely and to consult with US allies and partners.

He also spoke with Israeli Minister of Defence Yoav Gallant to discuss urgent regional threats and reiterated unwavering US support for Israel's defence.

During the call, Austin made clear that Israel could count on full US support to defend Israel against any attacks by Iran and its regional proxies, his spokesperson said on Saturday.

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