Israel-Gaza-Lebanon updates: IDF orders evacuations in Beirut as huge blast hits city

President Joe Biden said Tuesday the U.S. is prepared to help Israel defend against the Iranian missile attack.

Biden and Vice President Kamala Harris are monitoring the Iranian attack from the White House Situation Room and receiving regular updates from their national security team. Biden directed the U.S. military to aid Israel's defense against Iranian attacks and shoot down missiles.

Before the attack began, he posted on X that he and Vice President Kamala Harris had convened their national security team.

He said as well that the U.S. was ready to protect American personnel in the region.

Read more on the response from the Biden administration.

Republican Sen. Lindsey Graham of South Carolina condemned Iran's missile attack on Israel, calling it a "breaking point" on Tuesday and urging President Joe Biden's administration to respond.

“This missile attack against Israel should be the breaking point and 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.

Graham called for oil refineries to be "hit and hit hard" and said his prayers are "with the people of Israel."

-ABC News' Allison Pecorin

The Islamic Revolutionary Guard Corps said moments ago the missile attack was a retaliation for different assassinations carried out by Israel, Mehr News Agency reported.

The IRGC said the operation will continue if Israel does not stop, Mehr News Agency reported.

Hassan Nasrallah, the leader of Hezbollah, a key ally of Iran, was killed in a strike in Beirut last week, while a top member of the IRGC was also killed.

Israel Defense Forces spokesman Daniel Hagari issued remarks Tuesday evening, announcing that missiles had been launched from Iran toward Israel.

He said messages have been sent to cellphones, warning Israeli citizens in certain areas to enter "protected space" and to seek shelter if they hear sirens.

Hagari added that if citizens hear explosions, they may be the result of interceptions or impacts.

"We are strong and can handle this event as well," Hagari said. "The IDF is doing and will continue to do everything necessary to protect the civilians of Israel. The IDF is fully prepared for both defense and offense at peak readiness."

-ABC News' Jordana Miller