Richardson chided Illinois Sen.and former North Carolina Sen. for the criticism of Clinton, and predicted that he will win the nomination in part because he is running a positive campaign.
"I think that Senators Obama and Edwards should concentrate on the issues and not on attacking Senator Clinton," said Richardson, who officially added his name to the New Hampshire ballot. "It's OK to get aggressive on the issues, but to make personal attacks on somebody's attachments to lobbyists, that's not the kind of positive tone I want to see."
Edwards recently increased his criticism of Clinton, calling her part of a corrupt Washington system. The Clinton campaign responded that after decrying personal criticism in his 2004 campaign, Edwards has made them part of his daily routine this time.
Richardson said there will be plenty of time to get negative in the general election.
"Now is not the time to start food fights," he said.
Also Tuesday, Richardson began airing a new television commercial in Iowa focusing on his character and underscoring differences with his rivals on how to extricate the country from the war in Iraq.
The commercial will air alongside a separate spot touting Richardson's role in gaining the release of two hostages in Iraq.
"I am Bill Richardson and when I began this campaign for president I was not sure what to expect," Richardson says in the new ad. "I knew I would not have every answer, but I will always tell you what I really believe. And I will never mislead you."
The spot also emphasizes what Richardson sees as big differences with other Democratic candidates in getting out of Iraq. Richardson, the governor of New Mexico, says he would pull troops out far more quickly than rivals and suggests they are misleading voters because other candidates would leave thousands of troops in place.
"I will get every soldier out," Richardson says in the ad. "You cannot say you will end the war if you plan to leave thousands of troops behind. The Iraqis sure will not think the war is over."
A former energy department secretary and ambassador to the United Nations, Richardson argues that he is far better qualified to deal with issues like Iraq than candidates who have little experience in foreign policy.
"If you are wondering if anyone can really do all this, just look at what I have done in my life and how I have done it," he says.
Richardson has aired television commercials in Iowa as heavily as most of his rivals, but polls indicate he hasn't broken into the top tier of contenders for the state's leadoff precinct caucuses in January.