Condolences and support poured in for Sen. John McCain and his family on Friday, following the announcement that the senior Arizona senator was discontinuing medical treatment for brain cancer.

McCain was diagnosed with a glioblastoma, an aggressive form of brain cancer in July 2017, and has been home in Arizona since December of last year.

READ: Arizona Sen. John McCain ending treatment for brain cancer, family says

Jeff Flake kept his immediate response to Twitter, saying simply, "God bless and keep this wonderful man and his family."

Statement from Gov. Doug Ducey:

"John McCain is an American hero, always putting country before self. From Vietnam to the halls of the U.S. Senate, the spirit of service and civility that has guided Senator McCain's life stands as a model for all Americans, regardless of political affiliation. Angela and I had the great privilege of visiting with Senator McCain and Cindy in May. Then and now, our prayers and our hearts are with them and their entire family."

Statement from Representative Martha McSally:

"John McCain's life has been one of service and sacrifice. His strength and resolve enabled him to endure 5.5 years as a prisoner of war, and to continue to serve his country for decades. I have been praying for Senator McCain and his family during this difficult time, and continue to ask for God's grace and comfort for him and his family.”

Tweet from Representative Kyrsten Sinema:

Tweet from DPS Director Frank Milstead:

PHOTOS: Sen. John McCain through the years

Tweet from Senate Majority Leader McConnell:

Tweet from former Sec. of State John Kerry:

Tweet from Speaker Paul Ryan:

Tweet from Mitt Romney:

Tweet from Senator Chuck Schumer:

Tweet from Senator Bob Dole:

Tweets from Senator Dianne Feinstein:

Tweets from Senator Lindsey Graham:

Tweet from House Minority Leader Nancy Pelosi:

Tweet from Jeb Bush: