Trump and Obama lead tributes as John McCain is diagnosed with brain cancer

US former presidential candidate Senator John McCain has been diagnosed with brain cancer.

The discovery of McCain’s glioblastoma, an aggressive cancer, was discovered after he had a blood clot removed above his left eye.

Whilst the politician is recuperating at his home in Arizona, he has received a wealth of support from political allies, enemies and strangers – and here are but a few.

John McCain is an American hero & one of the bravest fighters I've ever known. Cancer doesn't know what it's up against. Give it hell, John.— Barack Obama (@BarackObama) July 20, 2017

As he’s shown his entire life, don’t bet against John McCain. Best wishes to him for a swift recovery.— Bill Clinton (@BillClinton) July 20, 2017

Past presidents Barack Obama and Bill Clinton might be Democrats while McCain is a Republican, but their words were warm and assured towards the war veteran.

Current president Donald Trump and vice-president Mike Pence also shared messages of support.

Melania and I send our thoughts and prayers to Senator McCain, Cindy, and their entire family. Get well soon. https://t.co/fONWVlmYyz— Donald J. Trump (@realDonaldTrump) July 20, 2017

Karen & I are praying for @SenJohnMcCain. Cancer picked on the wrong guy. John McCain is a fighter & he'll win this fight too. God bless!— Vice President Mike Pence (@VP) July 20, 2017

McCain, 80, served in Vietnam and has had a lifetime of near death experiences including surviving the July 1967 fire and explosion on the USS Forrestal that killed 134 sailors.

In October 1967, his navy aircraft was shot down into Truc Bach Lake in Hanoi, and he spent more than five years in a North Vietnamese prison.

John and I have been friends for 40 years. He's gotten through so much difficulty with so much grace. He is strong - and he will beat this.— Joe Biden (@JoeBiden) July 20, 2017

John McCain is as tough as they come. Thinking of John, Cindy, their wonderful children, & their whole family tonight.— Hillary Clinton (@HillaryClinton) July 20, 2017

John McCain is a hero, one of the most respected senators and a friend. The hopes and prayers of the nation are with him and his family.— Bernie Sanders (@BernieSanders) July 20, 2017

Politicians including former presidential hopefuls Hillary Clinton and Bernie Sanders, and former vice-president under Obama’s administration Joe Biden shared their thoughts.

South Carolina Republican Senator Lindsey Graham said he spoke to McCain on Wednesday over the phone.

He said his close friend told him: “Yeah, I’m going to have to stay here a little bit longer, take some treatments.

“I’ll be back.”

John McCain a patriot and straight shooter. He loves his country and sacrificed greatly for it. Thoughts and prayers for him and his family.— Bill O'Reilly (@BillOReilly) July 20, 2017

John McCain, a American patriot, will fight w/ the ferociousness he's shown other life challenges. The world prays for you to get well.— Eric Schiffer (@ericschiffer) July 20, 2017

McCain has run for presidency twice but was thwarted both times.

After losing to Obama in an electoral landslide in 2008, McCain returned to the Senate, determined not to be defined by a failed presidential campaign.

The well-wishing for McCain’s recovery has been cross-party and apolitical and is evident of the respect for the man – something many chose to point out.

John McCain is an example of how someone can have almost none of the same politics as you, and be a thoroughly good and heroic human being.— Matt Haig (@matthaig1) July 20, 2017

In this moment, no one should care in the slightest about political stances. John McCain is an American hero. Period.

Pray for him.

— Josh Hammer (@josh_hammer) July 20, 2017

Before I ever met John McCain, I was in awe of him. I've gotten to know him pretty well over the last couple of decades, and I still am.— Bill Kristol (@BillKristol) July 20, 2017

Let’s hope he gets well soon.

- Press Association