'Obama's campaign is all about division and hatred,' Romney

US Republican presidential candidate Mitt Romney attacked President Barack Obama again for running a campaign that was "all about division and attack and hatred."

Romney's comments in an interview with CBS came as the two camps clashed over the tone of the campaign with the Obama campaign on Tuesday calling the Republican standard bearer "unhinged."

"The president's campaign is all about division and attack and hatred," Mitt Romney told CBS.

"My campaign is about getting the US back to work and creating greater unity in this country, which of course has always been the source of America's vitality and strength."

"The president seems to be running just to hang onto power -- I think he'll do anything in his power to try to get reelected," he said.

Romney also took aim at Vice President Joe Biden whose charge in the former slave state of Virginia Tuesday that Romney's banking policies would "put y'all back in chains" set off a firestorm of Republican criticism.

"I think comments of this nature sink the White House just a little lower," Romney said, calling the remark an "unfounded charge."

"The comments of the vice president as I heard them were one more example of a divisive effort to keep from talking about the real issues."

On Tuesday, Romney told Obama to take his "hate" home to Chicago which prompted the president's camp to brand him "unhinged."

Romney laughed off the charge: "I think 'unhinged' would have to characterize what we've seen from the president's campaign."

US heads to the polls on November 6.