John McCain speaks at a 2008 campaign rally in Defiance, Ohio. "Our hearts and prayers are with you!" he added.
Final details of the service were not released as of Sunday morning.
He began life in 1936 at a US naval base located next to the Panama Canal; the grandson of a four-star US Navy admiral and the son of a naval officer, who would also become an admiral.
Former President Barack Obama and Michelle Obama issued a statement sending their "heartfelt condolences" to McCain's wife, Cindy and their family. "But all of us can aspire to the courage to put the greater good above our own", he said in a statement.
Sen. John McCain has died at the age of 81. And for that, we are all in his debt.
Bush also released a statement on Mr McCain's passing, writing how hard it is to imagine that such a vivid life has ended. "I think it's unfortunate that he had people around him - and they continued to be around him for a very long time - who weren't serving him well".
"He was a public servant in the finest traditions of our country".
Mr Biden wrote: "As a prisoner of war, John endured the worst of what human beings can do to one another". In politics, he fell short of his greatest ambition.
During his five-and-a-half year imprisonment, McCain endured cruel beatings and other forms of torture.
"And the spirit that drove him was never extinguished: we are here to commit ourselves to something bigger than ourselves".
"John McCain's life is proof that some truths are timeless".
"At his death, he had served the United States of America faithfully for 60 years".More news: Manchester City's Pep Guardiola wary of Tottenham Hotspur game switch
In a memoir published in May, McCain wrote that he hated to leave the world, but had no complaints.
It was a beloved Democrat congressman who would help teach McCain the benefits of working together. "However, it has to be said that he was a courageous man, a man of principle, a patriot of his country who had many trials in his life", said Slutsky, who chairs Russian parliament's worldwide affairs committee. He was a giant.
A US Senator since 1986, Senator McCain was the most senior and most trenchant Republican critic of President Donald Trump.
John McCain ran for president twice in 2000 and 2008. "His death is a loss for all who share that conviction".
During his concession speech in Sedona, McCain would say, "We're Americans. Our respectful thoughts go to his beloved ones".
Five senators were accused of improperly pressuring a regulatory agency on behalf of Keating, who was also a contributor to McCain's campaign. He will be remembered both in Europe and North America for his courage and character, and as a strong supporter of NATO. "Cindy and the McCain family have lost a loving husband and father".
Presidents and United States politicians from both parties have honoured Senator John McCain's decades of service to his country following his death at the age of 81. "Canadians join Americans tonight in celebrating his life and mourning his passing".
Mr McCain has been absent from the Senate for the most part of 2018, and some media reports said he last voted on December 7, 2017.
"The nation is in tears. Senator John McCain was a maverick and a fighter, never afraid to stand for his beliefs". In Australia, new Prime Minister Scott Morrison, who only assumed office on Friday, honoured "a true friend of Australia who was committed to strengthening the alliance between our two nations".
During his cancer treatment, McCain kept tabs on Washington from his Arizona home, where old friends and colleagues, including former Vice President Joe Biden, visited to check up on McCain and provide support.