The United States will deploy in Israel the THAAD advanced aerial defense system, the U.S. Department of Defense confirmed on Sunday, amid anticipation of an Israeli retaliation for Iran’s rocket strikes on it earlier this month.

Secretary of Defense Lloyd Austin approved the deployment of a THAAD battery and “associated crew of U.S. military personnel to Israel to help bolster Israel’s air defenses following Iran’s unprecedented attacks against Israel on April 13 and again on October 1,” the Pentagon announced in a statement.

THAAD, or Terminal High Altitude Area Defense, is a mobile anti-ballistic missile. U.S. President Joe Biden ordered the deployment, which is the third since 2019.

“The THAAD Battery will augment Israel’s integrated air defense system. This action underscores the United States’ ironclad commitment to the defense of Israel, and to defend Americans in Israel, from any further ballistic missile attacks by Iran,” Sunday’s announcement added.

The U.S. military deployed a THAAD battery, along with Patriot battalions, to bolster protections for American troops in the region late last year after the Oct. 7, 2023, Hamas massacre in southern Israel.

The United States also sent a THAAD unit to Israel in March 2019 for “training and an integrated air defense exercise,” according to the Pentagon. It also deployed the THAAD in Israel in 2021.

The manufacturer, Lockheed Martin, claims THAAD is the only U.S. system designed to intercept targets both inside and outside the atmosphere. THAAD was developed following the 1991 Gulf War as a countermeasure for long and medium-range missiles.