WASHINGTON (AP) — President Donald Trump will undertake one of the most solemn duties facing the commander in chief on Wednesday when he will witness the dignified transfer for two Iowa National Guard members killed in an attack in the Syrian desert.

The ritual at Dover Air Force Base in Delaware honors U.S. service members killed in action. Trump, who traveled to Dover several times in his first term, once described it as “the toughest thing I have to do” as president.

The two guardsmen killed in Syria on Saturday were Sgt. Edgar Brian Torres-Tovar, 25, of Des Moines, and Sgt. William Nathaniel Howard, 29, of Marshalltown, according to the U.S. Army. Both were members of the 1st Squadron, 113th Cavalry Regiment. The men have been hailed as heroes by the Iowa National Guard.

A U.S. civilian working as an interpreter, identified Tuesday as Ayad Mansoor Sakat of Macomb, Michigan, was also killed. Three other members of the Iowa National Guard were injured in the attack. The Pentagon has not identified them.

They were among hundreds of U.S. troops deployed in eastern Syria as part of a coalition fighting the Islamic State group.

During the process at Dover, transfer cases draped with the American flag holding the remains of fallen soldiers are carried from military aircraft to an awaiting vehicle. The vehicle then transports them to the mortuary facility at the base, where the fallen service members are prepared for their final resting place.

Trump told reporters over the weekend that he was mourning the deaths of the soldiers and vowed retaliation.

The attack Saturday comes after a rapprochement between the U.S. and Syria, bringing the former pariah state into a U.S.-led coalition fighting Islamic State.

Trump has forged a relationship with interim Syrian President Ahmed al-Sharaa, the onetime leader of an Islamic insurgent group who led the ouster of former President Bashar Assad.

Trump, who met with al-Sharaa last month at the White House, told reporters on Monday that the attack had nothing to do with the Syrian leader, who Trump described as “devastated by what happened.”

During his first term, Trump visited Dover in 2017 to honor a U.S. Navy SEAL killed during a raid in Yemen, in 2019 for two Army officers whose helicopter crashed in Afghanistan, and in 2020 for two Army soldiers killed in Afghanistan when a person dressed in an Afghan army uniform opened fire.