Updated 21:00
The US Senator and former presidential candidate John McCain will no longer receive treatment for brain cancer, his family has announced.
The 81-year-old has been receiving treatment for an aggressive brain tumour for more than a year.
Despite initially returning to the Senate following surgery, he has remained in his home state of Arizona for treatment since last December.
In a statement, the McCain family said: "Last summer, Senator John McCain shared with Americans the news our family already knew: he had been diagnosed with an aggressive glioblastoma, and the prognosis was serious.
"In the year since, John has surpassed expectations for his survival. But the progress of disease and the inexorable advance of age render their verdict. With his usual strength of will, he has now chosen to discontinue medical treatment."
The statement adds: "Our family is immensely grateful for the support and kindness of all his caregivers over the last year, and the continuing outpouring of concern and affection from John's many friends and associates, and the many thousands of people who are keeping him in their prayers. God bless and thank you all."
Reaction
Politicians across the political divide were among those who reacted to today's announcement by the McCain family.
Former US Secretary of State praised the Arizona senator as a 'brave man'.
God bless John McCain, his family, and all who love him — a brave man showing us once again what the words grace and grit really mean. https://t.co/9aiLxCF24E
— John Kerry (@JohnKerry) August 24, 2018
Madeleine Albright, another former Secretary of State under a Democratic president, said she is proud to call Senator McCain a friend.
I am proud to call John McCain a friend and partner in the fight for human rights and democratic values around the world. May God bless him and his family as they continue this journey.
— Madeleine Albright (@madeleine) August 24, 2018
Republican Senate majority leader Mitch McConnell, meanwhile, said he was 'so very sad' to hear the update.
Very sad to hear this morning’s update from the family of our dear friend @SenJohnMcCain. We are so fortunate to call him our friend and colleague. John, Cindy, and the entire McCain family are in our prayers at this incredibly difficult hour.
— Leader McConnell (@SenateMajLdr) August 24, 2018
Veteran senator
McCain was held as a prisoner of war during the Vietnam War, and after retiring from the Navy in the early 80s he began his career in politics.
Following two terms in the House of Representatives, he has been a senator for Arizona since 1987 - and has been re-elected five times.
He was chosen as the Republican candidate for the White House in 2008, but ultimately lost to Barack Obama.
While he has not actively taken part in Senate votes since late 2017, he has continued making public statements - including last month calling Donald Trump's press conference with Vladimir Putin in Helsinki "one of the most disgraceful performances by an American president in memory".
Last year, shortly after returning from brain surgery, he dramatically cast the deciding vote against repealing the so-called Obamacare healthcare legislation - sinking one of the Trump administration's key policy goals in the process.
Senator McCain has battled cancer before, having had malignant melanomas removed from his skin in the 1990s and 2000s.