DENVER - Mitt Romney responded today to criticism that he has not been using his running mate effectively, telling ABC News that he and Rep. Paul Ryan "hit the road pretty darn hard."

Romney has been criticized in recent days for spend time raising campaign cash instead of being on stump. He blamed that today on President Obama's decision to opt out of the federal campaign finance system. By not accepting federal funds for campaigning, it allows Obama to raise as much money as he wants.

"Well, Congressman Ryan and I are both working very hard," said Romney. "We, of course, recognize that part of a campaign is to have the funds to run advertising. Our president has done an unusual thing. President Obama is the first post-Watergate candidate to say he's not going to live by the federal spending rules. So he's raising unlimited amounts of money."

Romney has held more private fundraisers in the past few days than public events.

"To be competitive, we have to raise money so we can be on the air just like he is," he said. "And we also are very anxious to get out and speak with as many people as we can."

"Both Paul and I, we hit the road pretty darn hard," said Romney.

Romney and Ryan will campaign together in Ohio Tuesday, but it will be the first time the two have appeared together at an event since Sept. 1.

Wisconsin Gov. Scott Walker has been one of the most outspoken critics, after originally hailing Romney's pick of Ryan, telling a radio station according to the Milwaukee Journal Sentinel that the Romney campaign needs to use Ryan "out on the trail more effectively."

"They need to have more of him rub off on Mitt because I think Mitt thinks that way but he's going to be able to articulate that," said Walker. "I think too many people are restraining him from telling [his vision]."

Ryan responded to the criticism from Walker, saying, "I'm excited about my role and I feel very comfortable with it."

Romney's campaign has been previewing a so-called reset, one that was taken off track by the leaked videos last week from a fundraiser in which Romney referred to 47 percent of Americans who consider themselves as "victims" who rely too heavily on government aid.

Asked today what kind of reset voters will see going forward, Romney said he will be speaking "about the same topics" he has in the past, but will seek to contrast himself with the "status quo."

"I'm going to make sure that people understand that this is a different direction for the nation and that if they want the status quo, they can re-elect the person who has been leading us over the last four years," said Romney. "If they instead want to see this country go on a path that creates jobs and rising incomes, then they're going to have to vote for real and positive change, and that's what I represent."

Read a transcript of Romney's interview with ABC .

Romney criticizes Obama on Mideast and foreign policy.