With regional tensions at their highest since the Israel-Hamas war began six months ago, Biden pledged on Saturday that American support for Israel’s defense against attacks by Iran and its proxies is “ironclad.” The attack marked the first time Iran has launched a direct military assault on Israel, risking a wider regional conflict.

Biden made clear in a call to Israeli Prime Minister Benjamin Netanyahu that the U.S. would not participate in any offensive action against Iran, according to a senior administration official who was not authorized to publicly discuss the private conversation and spoke on condition of anonymity.

The U.S. and Israel had been bracing for an attack for days after Iran said it would retaliate for a suspected Israeli strike this month on an Iranian consular building in Syria that killed 12 people, including two senior Iranian generals in the Revolutionary Guard’s elite Quds Force.

“At my direction, to support the defense of Israel, the U.S. military moved aircraft and ballistic missile defense destroyers to the region over the course of the past week,” Biden said in a statement late Saturday. “Thanks to these deployments and the extraordinary skill of our servicemembers, we helped Israel take down nearly all of the incoming drones and missiles.”

Defense Secretary Lloyd Austin in a statement said the U.S. took out dozens of the attacks, but did not provide details on ships or aircraft involved in the operation that commanders had been preparing for over the past two weeks.

“Our forces remain postured to protect U.S. troops and partners in the region, provide further support for Israel’s defense, and enhance regional stability,” Austin said, adding that troops are standing ready to prevent any further conflict.

Biden had cut short a weekend stay at his Delaware beach house to meet with his national security team at the White House, returning to Washington minutes before Israeli officials confirmed that they had detected drones being launched toward their territory from Iran.

He convened a principals meeting of the National Security Council in the White House Situation Room to discuss the unfolding situation, the White House said, before speaking with Netanyahu.

“I told him that 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,” Biden said.

Biden added that he would convene a meeting of the Group of Seven advanced democracies on Sunday “to coordinate a united diplomatic response to Iran’s brazen attack.”

The Pentagon reported that Austin had spoken twice with his Israeli counterpart to praise the “extraordinary defensive measures and strong cooperation undertaken to defeat this Iranian attack against Israel” and again stated clearly that “Israel could count on full U.S. support to defend Israel against any future attacks by Iran and its regional proxies.” National security adviser Jake Sullivan also spoke with his counterpart to reinforce Washington’s “ironclad commitment to the security of Israel.”

National Security Council spokesperson Adrienne Watson said in a statement that “Iran has begun an airborne attack against Israel.” She added: “The United States will stand with the people of Israel and support their defense against these threats from Iran.”

Biden on Friday said the United States was “devoted” to defending Israel and that “Iran will not succeed.” Asked by reporters what his message was for Iran, the president’s only reply was: “Don’t.”

He ignored a question about what would trigger a direct U.S. military response.

The U.S., along with its allies, have sent direct messages to Tehran to warn against further escalating the conflict.

During the Israel-Hamas war in Gaza, there have been near-daily exchanges of fire between Israeli forces and the Iran-backed Hezbollah militant group along the Israel-Lebanon border. U.S. officials have recorded more than 150 attacks by Iran-backed militias in Iraq and Syria on U.S. forces at bases in those countries since war started on Oct. 7.

One attack in late January killed three U.S. service members in Jordan. In retaliation, the U.S. launched a massive air assault, hitting more than 85 targets at seven locations in Iraq and Syria.

Meantime, on Saturday, commandos from Iran’s paramilitary Revolutionary Guard rappelled from a helicopter onto an Israeli-affiliated container ship near the Strait of Hormuz and seized the vessel.

Watson, the NSC spokesperson, said the U.S. strongly condemned the seizure and urged Iran to release the ship and crew immediately.

“We will work with our partners to hold Iran to account for its actions,” she said.

Also Saturday, the Israeli-occupied West Bank also saw some of the worst violence since Hamas’ attack on Israel.