"Ibrahim al-Asiri, a senior al-Qa'ida (al-Qaida) bomb maker and terrorist coordinator, was killed two years ago in a United States counterterrorism operation in Yemen", Trump said in a White House statement.
Thursday's White House statement also confirmed al-Asiri's role in several prominent failed attacks carried out by the group.
It did not say why Trump is confirming al-Asiri's death now. "The United States will continue to hunt down terrorists like al-Asiri until they no longer pose a threat to our great Nation", he said in the statement.More news: 1 dead, 3 missing after hotel under construction collapses in New Orleans
In the Christmas Day bombing, a Nigerian man attempted to detonate explosives concealed in his underwear on a Northwest Airlines flight from Amsterdam to Detroit. It is believed the operation took place in midsummer.
Ibrahim Hassan al-Asiri was long wanted by American authorities for being the mastermind behind the failed 2009 plot to blow up a US- bound airplane.
Some congressional Republicans say the USA has abandoned its friends in the region, though Mr. Trump said he's watching closely and will punish Turkey for missteps.More news: Footage Released Showing Errol Spence's Horrific Crash That Ejected Him From Car
The death of al-Asiri was reported overseas two years ago, but was not confirmed by the U-S until now.
However, the bomb failed to explode and Abdulmutallab was tackled to the ground by a fellow passenger.
The explosive maker had also recruited his brother, Abdullah al-Asiri, as a suicide bomber in the attempted assassination of former Saudi Crown Prince Mohammed bin Nayef in 2009.More news: El Camino: A Breaking Bad Movie Review - 7 Ups & 2 Downs
He was widely credited with perfecting miniaturized bombs with little or no metal content that could make it past some airport security screening.