By Jeremy Diamond, CNN

(CNN) -- Just after midnight on Sunday night, the flag flying above the White House was hoisted back to full staff.

Since Saturday evening, it had been positioned at half-staff to mark the death of Sen. John McCain, the former Vietnam prisoner of war and onetime Republican nominee for President. His death had sparked an outpouring of tributes from across the political spectrum, except at 1600 Pennsylvania Avenue, where President Donald Trump has yet to utter a word about McCain since his passing.

The White House flag returned to its regular position even as other flags around Washington -- including at the US Capitol -- remained in the half-staff mourning position.

The contrast offered the latest reminder of the animosity that Trump has maintained for McCain, even after his passing.

Trump has yet to offer a single word of praise or recognition of McCain's service since he died Saturday after a battle with brain cancer. The White House offered no official statement, but Trump did tweet his "deepest sympathies and respect" to McCain's family.

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. He never apologized or walked-back his comments, despite the fact that McCain was imprisoned and tortured in Vietnam for more than five years.

Barring an official White House proclamation ordering flags nationwide to be flown at half-staff in McCain's honor, the top Senate Republican and Democrat on Monday requested that the Defense Department "provide necessary support so that US flags on all government buildings remain at half-mast through sunset on the day of Senator McCain's interment," Schumer's communications director said.

Defense Department guidelines call for flags to be flown at half-staff "from the day of death through the following day" in the event a US senator or member of Congress dies. But the President has the authority to order a longer period of mourning.

Even after McCain was diagnosed with an aggressive form of brain cancer, Trump continued to launch broadsides in McCain's direction, lambasting him for his critical "no" vote that thwarted a last-ditch Republican effort to partially repeal Obamacare. Earlier this month, during a signing event for the national defense spending bill named after McCain, Trump did not once mention the senator.

During the time he remained active in the Senate, McCain also expressed deep misgivings about Trump's job as President, criticizing his handling of world affairs and the example he has set for the country.

McCain also made clear he did not want Trump to attend his funeral service, instead choosing former Presidents George W. Bush, a Republican, and Barack Obama, a Democrat, to eulogize him. Vice President Mike Pence is expected to represent the White House at McCain's funeral service.