President Trump took part in a ceremony Saturday to honor four Americans killed in Syria last week, including Scott Wirtz, a former Navy SEAL working as a civilian contractor. The four were killed in a suicide attack by the Islamic State terrorist group.

"Will be leaving for Dover to be with the families of 4 very special people who lost their lives in service to our Country!" Trump tweeted earlier in the day, before heading to Dover Air Force Base in Delaware. The president stood stoned-faced and saluted as the remains of Wirtz were carried in a flag-draped casket from a C-17 military aircraft into a waiting gray minivan.

Transfers of the three other victims in the attack were also held but the press was not allowed to view them. Trump met privately with the victims' family members. The Pentagon identified two of the other victims as Army Chief Warrant Officer Jonathan Farmer, of Florida, and Navy Chief Cryptologic Technician Shannon Kent, of New York.

"When I'm going to meet relatives of some of our great, great heroes that have fallen, I think it might be the toughest thing I have to do as president," Trump told reporters after the ceremony.

Trump announced last month that he would remove the approximately 2,000 U.S. forces in Syria but has faced resistance from some senior advisers on the matter who warn that could boost Russia and Iran in the region. Defense Secretary Jim Mattis resigned over the decision. The White House's plans for removal have been in flux as a result.