Washington — John McCain is getting a presidential farewell, but not from the actual sitting president.At McCain's request, former Presidents Barack Obama, a Democrat, and George W. Bush, a Republican, are speaking about the six-term senator on Saturday at Washington National Cathedral. It is the last event in Washington, where McCain lived and worked over four decades, and part of McCain's five-day, cross-country funeral procession. He died Aug. 25 at age 81.McCain's procession on Saturday morning and was set to come near the White House as it traveled from the US Capitol, where the casket was lying in state overnight, to the cathedral. It stopped at the Vietnam Veterans Memorial, where McCain's wife, Cindy, placed a wreath.President Donald Trump was told to stay away but isn't far. The president planned to remain in Washington this weekend. Two of his top aides, White House chief of staff John Kelly and Defense Secretary James Mattis, flanked Cindy McCain as she approached the memorial.McCain was a decorated veteran who was held for more than five years as a prisoner of war in Vietnam. He refused early release. Trump obtained deferments for his college education and a foot ailment.The memorial stop provided another contrast with Trump in McCain's carefully designed funeral procession, but the speeches by the former presidents are expected to carry special weight.McCain had long urged the Senate and the polarised nation to recognise the humanity even in bitter political opponents. McCain's request for speeches by the former presidents, to some, represents that ideal."We weaken our greatness when we confuse our patriotism with tribal rivalries that have sown resentment and hatred and violence in all the corners of the globe," McCain wrote in his farewell letter to the nation, read posthumously by a longtime aide. "We weaken it when we hide behind walls, rather than tear them down, when we doubt the power of our ideals, rather than trust them to be the great force for change they have always been."By all accounts, McCain ended up liking both Bush and Obama but was not especially close to either man."John McCain and I were members of different generations, came from completely different backgrounds, and competed at the highest level of politics," Obama said in a statement after McCain's death. "But we shared, for all our differences, a fidelity to something higher — the ideals for which generations of Americans and immigrants alike have fought, marched, and sacrificed."Bush delivered McCain a decisive defeat in the race for the GOP presidential nomination in 2000. Obama defeated McCain eight years later in the general election.After his death, Bush called McCain "a man of deep conviction and a patriot of the highest order. He was a public servant in the finest traditions of our country. And to me, he was a friend whom I'll deeply miss".McCain's service and dedication to working across the aisle — even as he sometimes infuriated his opponents — was a major theme of Friday's ceremony in the Capitol Rotunda.Of those who spoke at Friday's ceremony, fellow Republican Mitch McConnell had perhaps the fullest sense of the McCain experience. The two had served in the Senate together since McCain's 1986 election."Depending on the issue, you knew John would either be your staunchest ally or your most stubborn opponent," McConnell recalled. "At any moment, he might be preparing an eloquent reflection on human liberty — or a devastating joke, served up with his signature cackle and that John McCain glint in his eye."But just about anyone who worked in the Capitol over the past 35 years could attest to McCain's iron will and what House Speaker Paul Ryan called his "distinct brand of candor.""With John, it was never feigned disagreement. The man didn't feign anything," Ryan said. "He just relished the fight.""This," Ryan added of McCain, "is one of the bravest souls our nation has ever produced."McCain is to be buried Sunday at his alma mater, the US Naval Academy, next to his best friend from the Class of 1958, Adm. Chuck Larson."Back," McCain wrote on the last page of his recent memoir, "where it began".