An American operation killed al-Qaeda’s top leader in Yemen last week, President Donald Trump confirmed Thursday night.

Qasim al-Raymi had been targeted in a botched US Navy SEAL raid in 2017, just days after Trump took office, that led to the death of the first American service member in combat under the new administration. Recently, the top lieutenant to al-Qaeda leader Ayman al-Zawahiri had taken credit for the shooting at a US naval air base in Florida that killed two American service members.

The Pentagon has long watched al-Qaeda in the Arabian Peninsula, known by the acronym AQAP, that famously hatched a failed plot to blow up an American jetliner with an underwear bomb. A White House statement did not clarify the nature of the operation that killed Raymi, though The New York Times reported last week that the terror leader died in an airstrike.

Current and former US officials said Raymi, who became AQAP’s chief in 2015 and whose activities date back to al-Qaeda training camps in Afghanistan in the 1990s, is a very significant development. Trump said in a statement Thursday that the death “further degrades AQAP and the global al-Qaeda movement,” bringing the United States closer to eliminating the group.