John McCain, are back at full-staff.
While the flags at the White House were raised, the flags at the U.S. Capitol remained at half-staff on Monday to honor the Arizona Republican.
But they were flying at full-staff by Monday morning, even as the flags at the US Capitol remained at half-staff.
"He was a warrior, he was also a peace maker, and of course he fought and suffered during the Vietnam war, but then later as a senator he was one of the leaders who helped bring our countries back together, and helped the United States and Vietnam normalize our relationship and now become partners and friends", stated Daniel Kritenbrink, U.S. Ambassador to Vietnam.
And Mr Trump himself issued flag flying proclamations following mass shootings in Las Vegas and Parkland, Florida.
Trump issued a proclamation upon the death of the Rev. Billy Graham in February that ordered flags on all federal buildings at half staff on Graham's day of interment.
The White House did not immediately respond to a request for comment.
Former presidents George W Bush and Barack Obama are expected to speak at a service at Washington National Cathedral on Saturday. "Our hearts and prayers are with you!" he wrote on Saturday night.
Instead, both the president and Vice-President Mike Pence offered their condolences to the senator's family via Twitter. Plans call for McCain, a former Navy pilot, to be buried Sunday in the cemetery on the grounds of the U.S. Naval Academy in Annapolis.
McCain was one of Trump's sharpest critics, and made clear in one of his final wishes as he struggled with brain cancer that he did not want the president to attend his funeral.
Early in his presidential bid, Trump - who received five deferments to avoid military service in Vietnam - infamously maintained that McCain was not a war hero because he had been captured. The senator will lie in state at the Arizona state capitol on Wednesday with his first memorial service taking place in Phoenix on Thursday.