McCain was reportedly diagnosed with a brain tumour on July 2017, and was since undergoing treatment. But on Friday his family announced he had chose to discontinue that treatment. "Our thoughts and prayers go out to his wife, Cindy, and all the McCain family during this time".
McCain, who was being treated at his Arizona ranch, was surrounded by his wife Cindy and his family during his final hours. But in this loss, and in this sorry, I take comfort in this: John McCain, hero of the republic and to his little girl, wakes today to something more glorious than anything on earth. He lost to Barack Obama, who, along with George W. Bush, will reportedly eulogize McCain at his funeral, which has been planned for the past year.
Donald Trump, whom Mr McCain has strongly criticised, tweeted his "deepest sympathies" to Mr McCain's family but made no comment about his life.
Sen. Ben Cardin: "John McCain was an honorable public servant who sacrificed greatly to serve his country and the people of Arizona". McCain was a prisoner of war for more than five years.
North Dakota Gov. Doug Burgum called McCain "a true American hero, patriot and statesman" in a statement.
Trump has been criticised for his feud with McCain, which started after he underplayed the senator's renowned military service during the 2016 presidential campaign. "But, to me, more than anything, John was a friend".
Sen. Lindsey Graham, a very close friend of McCain at the senate, said: "America and Freedom have lost one of her greatest champions". McCain was the unsuccessful Republican candidate for the 2008 presidential election and was an active voice in USA foreign policy debate, as Chairman of the Senate Armed Services Committee from January 2015 until his death.
It has been confirmed that former Vice President Joe Biden will speak at a separate service to be held in McCain's home state of Arizona, where McCain had served as US Senator since 1987. "My condolences go out to the McCain family and the people of Arizona".
McCain inveighed against Trump over the latter's meeting with Russian President Vladimir Putin in Helsinki.
McCain spent more than three decades in the Senate, looming large in debates over war and peace and the moral direction of the nation. "His love and his care, ever present, always unfailing, took me from a girl to a woman - and he showed me what it is to be a man".
Sarah Palin, whom McCain plucked from obscurity to become his 2008 White House running mate, described him as "an American original" and "a fighter, never afraid to stand for his beliefs".
Democratic leader Nancy Pelosi said the "nation is in tears" and noted McCain's "deep patriotism, outstanding bravery and undaunted spirit".