John McCain's campaign hit back at Madonna on Sunday after the pop diva began her world tour with a concert that bracketed the US presidential candidate with Adolf Hitler.

McCain campaign spokesman Tucker Bounds angrily condemned the segment of Madonna's concert in Cardiff, Wales, that appeared to draw a comparison between McCain, Hitler and Zimbabwean strongman Robert Mugabe.

"The comparisons are outrageous, unacceptable and crudely divisive all at the same time," Bounds said in a statement reported by Fox News.