The United States warned Iran that it would face severe consequences for its ballistic missile attack on Israel on Tuesday, saying the barrage marked a significant escalation but appeared to have been thwarted.

U.S. National Security Adviser Jake Sullivan said U.S. military forces in the region helped Israel defeat the attack and that the Biden administration was consulting with Israel on a response.

“This is a significant escalation by Iran, a significant event,” Sullivan told reporters at the White House. “We have made clear that there will be consequences, severe consequences, for this attack, and we will work with Israel to make that the case.”

Sullivan did not specify what those consequences might be, but he stopped short of urging restraint by Israel as the U.S. did in April when Iran carried out a drone and missile attack on Israel.

Sullivan said President Joe Biden’s administration was still monitoring the situation and collecting information.

Iran launches salvo of ballistic missiles at Israel, warns against response

Iran’s ballistic missile attack marks a steep escalation of tensions in the region, despite months of intense negotiations by the Biden administration and regular pledges that a ceasefire to end the Gaza conflict was imminent.

Biden, in the waning months of his term, already faces sharp criticism at home and abroad for U.S. military support of Israel, as does his Vice President and the Democrats’ presidential candidate Kamala Harris.

Iran fired a salvo of missiles at Israel in retaliation for Israel’s air and ground campaign against Tehran’s Hezbollah allies in Lebanon, and Israel vowed a “painful response” against its enemy.

Israel said more than 180 missiles were launched into Israel from Iran. Israeli air defenses intercepted them.

The Pentagon said two U.S. Navy destroyers fired about a dozen interceptors against Iranian missiles aimed at Israel.

Pentagon spokesperson Major General Patrick Ryder described the attack as significant and said the United States supported Israel’s right to defend itself.

Ryder said the attack was about twice the scope of Iran’s April attack on Israel in terms of the number of ballistic missiles fired.

State Department spokesperson Matthew Miller said the U.S. was calling on every nation in the world to join it in condemning Iran’s attack, calling it brazen and unacceptable.

U.S. officials said they had no warning from the government of Iran that they were going to launch such an attack.