DUBAI— The US military launched interceptor missiles during an attack by Yemen’s Houthi rebels that targeted the United Arab Emirates during a visit by Israel’s president, the second-such time American troops have opened fire, officials said.

The acknowledgement by the White House and Pentagon late Monday represent a widening American involvement in Yemen’s yearslong war, a conflict that President Joe Biden declared nearly a year ago “has to end.”

While the U.S. has ended offensive support to the Saudi-led coalition fighting on behalf of Yemen’s exiled government, their involvement in defending the UAE comes as the rebel Houthis have declared Al-Dhafra Air Base in Abu Dhabi a target. Al-Dhafra hosts some 2,000 American troops and has served as a major base of operations for everything from armed drones to F-35 stealth fighters.

Speaking from the White House, press secretary Jen Psaki said the U.S. military “responded to an inbound missile threat on the UAE.

“This involved the employment of Patriot interceptors to … (support) efforts by the armed forces of the UAE,” Psaki said. “I would say we are working quite closely with them.”

At the Pentagon, press secretary John Kirby said that “U.S. Patriots were fired, but it was the Emirati surface-to-air missiles that actually engaged the targets.”

Asked if that would include targets outside of Al-Dhafra, Kirby said: ” If we can help defend our Emirati partners, we’re going to do that.”

Biden also mentioned the attack on the UAE at the White House during a visit by Qatar’s ruling emir, Sheikh Tamim bin Hamad Al Thani, saying that “America will have the backs of our friends in the region.”

The Emirati military, as with a similar attack last week, did not acknowledge that the American military opened fire. The autocratic UAE, a federation of seven sheikhdoms on the Arabian Peninsula, has threatened criminal charges against anyone filming an attack or outgoing interceptor fire.

The UAE’s state-run WAM news agency reported Monday’s interception, saying “the attack did not result in any losses, as the remnants of the ballistic missile fell outside the populated areas.” It wasn’t immediately clear where the remnants fell, though American Patriot missiles are thought only to be deployed at Al-Dhafra.

The attack came just before Israeli President Isaac Herzog’s visit to Dubai Expo 2020.

A Jan. 17 attack on Abu Dhabi by the Houthis killed three people and wounded six at an Abu Dhabi National Oil Co. fuel depot near Al-Dhafra.

The war in Yemen has become the world’s worst humanitarian crisis. Saudi-led airstrikes using American-made bombs have killed schoolchildren and civilians. The UAE paid off local al-Qaida fighters to avoid fighting and controlled prisons where torture and sexual abuse were rampant. Meanwhile, Yemen’s Houthi rebels have employ child soldiers and indiscriminately laid landmines during the country’s civil war.