White House calls Iranian missile attack 'significant escalation'

White House national security adviser Jake Sullivan on Tuesday called Iran's missile attack against Israel a "significant escalation" and said the Biden administration is determining how to respond.

“Obviously this is a significant escalation by Iran, a significant event, and it is equally significant that we were able to step up with Israel and create a situation in which no one was killed in this attack in Israel, so far as we know at this time," Sullivan told reporters.

"We are now going to look at what the appropriate next steps are to secure first and foremost American interests, and then to promote stability to the maximum extent possible as we go forward," he added.

Iran launched a barrage of missiles at Israel on Tuesday, shortly after the U.S. warned an attack was imminent. The attack appeared to be over within an hour of starting.

Sullivan said the attack appeared to be "defeated and ineffective.”

President Biden reiterated Sullivan’s comments, saying “the attack appears to have been defeated and ineffective” and attributed that to the Israeli military capability, the U.S. military and the “intensive planning” between the U.S. and Israel.

The president also stressed his administration’s unwavering support for Israel.

Vice President Harris later on Tuesday voiced her support for ensuring Israel has the ability to defense itself.

“Iran is not only a threat to Israel, Iran is also a threat to American personnel in the region, American interests and innocent civilians across the region who suffer at the hands of Iran-based and backed terrorist proxies. We will never hesitate to take whatever action is necessary to defend us forces and interests against Iran and Iran-backed terrorists,” she said.

Israeli military spokesperson Rear Adm. Daniel Hagari said that missiles had just been launched from Iran around 7:30 p.m. local time in Israel. Sirens sounded across Israel, according to the military.

The Israeli military later confirmed the end of the barrage in a post that told Israeli citizens it was safe to leave their shelters.

The Iranian blitz comes after a bruising and nearly yearlong cross-border conflict between Hezbollah, a major proxy group for Tehran, and Israeli forces. The fight, tied to the ongoing war in Gaza, has severely crippled Hezbollah after Israel eliminated most of its command structure in the past month. 

This story was updated at 5:08 p.m.