McCain penning 'no-holds-barred' memoir

In "The Restless Wave: Good Times, Just Causes, Great Fights, and Other Appreciations," the Arizona Republican will offer "his no-holds-barred opinions on the current developments coming out of Washington," according to Simon & Schuster.

The memoir, co-authored by McCain's longtime speechwriter Mark Salter, will cover the 2008 election through the present and will discuss domestic and foreign relations challenges facing the US.

"Candid, pragmatic, and always fascinating, John McCain holds nothing back in his latest memoir," the publisher's description said.

McCain and President Donald Trump have traded barbs since the 2016 campaign and neither McCain nor Salter have shied away from criticizing the commander-in-chief.

The Arizona Republican most recently took Trump to task for congratulating Russian President Vladimir Putin on his election victory.

"An American president does not lead the Free World by congratulating dictators on winning sham elections," McCain said in a statement. He has also condemned the President in November for saying he believed Putin on US election meddling and warned against US isolationism in a speech in October. In January, McCain published an op-ed telling Trump to stop attack the media.

Salter has frequently denounced Trump on Twitter.

"325 million people in this country and we elected the worst one president," he wrote in March.

McCain is battling a primary glioblastoma, an aggressive type of brain tumor. His wife, Cindy, said in early March that he was "doing fine."