WASHINGTON (AP) — President Donald Trump is heading to Dover Air Force Base to pay tribute to the four Americans killed in a suicide bomb attack in Syria this week.

The Delaware trip hadn’t been on the president’s public schedule for Saturday, but he tweeted the news before he left the White House.

The deceased are:

Army Chief Warrant Officer 2 Jonathan R. Farmer, 37, of Boynton Beach, Florida. Farmer was assigned to 3rd Battalion, 5th Special Forces Group (Airborne), Fort Campbell, Kentucky.

Navy Chief Cryptologic Technician (Interpretive) Shannon M. Kent, 35, of upstate New York. Kent was assigned to Cryptologic Warfare Activity 66, based at Fort George G. Meade, Maryland.

The bombing in Manbij was the deadliest assault on U.S. troops in Syria since American forces moved into the war-torn country in 2015.

The attack came about a month after Trump said the Islamic State group had been defeated and he was withdrawing U.S. forces from the country.

The Islamic State claimed responsibility for the attack.