President Joe Biden said Tuesday he directed the U.S. military to help Israel shoot down Iranian missiles -- an attack, Biden said, that appears to have been "defeated and ineffective."

"This is testament to Israeli military capability and the U.S. military," Biden said in his first on-camera remarks on the issue. "It's also a testament to intensive planning between the United States and Israel to anticipate and defend against the brazen attack we expected."

"Make no mistake, the United States is fully, fully, fully supportive of Israel," Biden added.

Vice President Kamala Harris, in her own remarks, said she "fully supported" Biden's order to help shoot down the Iranian missiles and that her support for Israel was "unwavering."

"I condemn this attack unequivocally," Harris said. "I'm clear-eyed. Iran is a destabilizing, dangerous force in the Middle East, and today's attack on Israel only further demonstrates that fact."

Officials called Tuesday's events a "significant escalation" from Iran in retaliation for the killing of Hezbollah leader Hassan Nasrallah last week.

Iran launched about 200 ballistic missiles at various targets inside Israel, the Pentagon's Maj. Gen. Pat Ryder told reporters. Two U.S. Navy destroyers located in the eastern Mediterranean -- the USS Bulkeley and USS Cole -- fired "approximately a dozen" missile interceptors at the incoming barrage, Ryder said.

National security adviser Jake Sullivan, joining the White House press briefing, said at this time the administration does not know of "any damage to aircraft or strategic military assets in Israel."

Biden and Harris monitored the Iranian attack against Israel from the White House Situation Room and received regular updates from their national security team, Sullivan said.

Biden said his team has been in constant contact with Israeli officials and would continue to share updates. He has not yet spoken to Netanyahu.

Asked how he would like Israel to respond, Biden said it was an "active discussion."

"That's an active discussion right now. We're gonna get all the data straight, we've been in constant contact with the Israeli government and our counterparts, and that remains to be seen," he said.

The Biden administration has long opposed a wider regional conflict in the Middle East amid the Israel-Hamas war.

Asked at the White House briefing whether Biden would recommend Israel have a limited response as he did after Iran's attack in Israel in April, Sullivan declined to say.

"I will not, from this podium, share the president's recommendations. He will have the opportunity to share them directly. We're going to have, as I said, ongoing consultations with the Israelis this afternoon and this evening. It is too early for me to tell you anything publicly in terms of our assessment or in terms of what our expectations are of the Israelis or the advice that we will give them," Sullivan said.

Before the strike began, the Pentagon said Secretary of Defense Lloyd J. Austin spoke with Israeli Minister of Defense Yoav Gallant to discuss the threat of an imminent Iranian attack against Israel.

President Biden had been scheduled to hold a call with rabbis ahead of the Jewish High Holidays but the White House said that call has now postponed.

One of the first reactions from Capitol Hill came from South Republican GOP Sen. Lindsey Graham, who called Iran's missile attack on Israel a "breaking point" and called for a response.

"I would urge the Biden Administration to coordinate an overwhelming response with Israel, starting with Iran's ability to refine oil," Graham said in a statement. He called for oil refineries to be "hit and hit hard."

House Republican leadership later released a joint statement urging the Biden-Harris administration to send a strong message to Iran following the attack on Israel. House Speaker Mike Johnson was briefed on the Iranian strikes on Israel, according to his spokesperson.

"The world is watching as Israeli families seek safety and shelter as waves of missile attacks light up the sky," the joint statement read. "We pray for their safety and urge the Biden-Harris Administration to deliver a strong message to the Iranian regime that this unjustified violence and terror must end. The strategy of appeasement has failed, and a policy of interdiction is not enough."

Senate Republican Leader Mitch McConnell also said Iran should face "severe consequences" and called on the administration to "replenish Israel's supply of critical munitions" following Iran's missile attack on Israel.

"It is not enough to issue statements. It is not enough to intercept missiles and drones moments before they reach civilians in Israel or U.S. personnel in the Red Sea. It is time for America to act like the friend of Israel we claim to be. It is time to replenish Israel's supply of critical munitions," McConnell said.

ABC News' Luis Martinez and Lauren Peller contributed to this report.