Joe Walsh has pulled out of a concert scheduled for July 18 in Cleveland, which turned out to be a launch for the Republican National Convention.

He says he originally booked the gig thinking it was a benefit for America's veterans.

"It was my understanding that I was playing a concert which was a non-partisan event to benefit the families of American veterans," Walsh says, via Facebook.

"Today it was announced that this event is, in fact, a launch for the Republican National Convention.

In addition, my name is to be used to raise sponsorship dollars for convention-related purposes.

Therefore, I must humbly withdraw my participation in this event with apologies to any fans or veterans and their families that I might disappoint."

Walsh said he is also upset with the tone of this year's campaign, citing "the rampant vitriol, fear-mongering and bullying coming from the current Republican campaigns. It is both isolationist and spiteful," he said.

"I cannot in good conscience endorse the Republican party in any way."