"I'm very disappointed in the article. It's not true," the likely Republican presidential nominee said as his wife, Cindy, stood beside him during a news conference called to address the matter.
"I've served this nation honorably for more than half a century," said McCain, a four-term Arizona senator and former Navy pilot. "At no time have I ever done anything that would betray the public trust."
"I intend to move on," he added.
McCain described the woman in question, lobbyist Vicki Iseman, as a friend.
He made his remarks in Ohio before heading to Michigan, where he was scheduled to meet with executives from the Detroit Three auto companies and tour the Ford Motor Co. plant in Wayne where the popular Ford Focus is assembled. McCain was to speak with reporters on the assembly floor. He also had a Troy, Mich., fundraiser planned for Thursday evening.
The newspaper quoted anonymous aides as saying they had urged McCain and Iseman to stay away from each other prior to his failed presidential campaign in 2000. (Read the New York Times story) In its own follow-up story, The Washington Post quoted longtime aide John Weaver, who split with McCain last year, as saying he met with lobbyist Iseman and urged her to steer clear of McCain. (Read the Washington Post story.)
"As the presumptive nominee, McCain left no wiggle room for himself or his party with his absolute denials of every key charge and insinuation raised by the New York Times article," said CBSNews.com senior political editor Vaughn Ververs.
Weaver told the Times he arranged the meeting before the 2000 campaign after "a discussion among the campaign leadership" about Iseman.
But McCain said he was unaware of any such conversation, and denied that his aides ever tried to talk to him about his interactions with Iseman.
"I never discussed it with John Weaver. As far as I know, there was no necessity for it," McCain said. "I don't know anything about it," he added. "John Weaver is a friend of mine. He remains a friend of mine. But I certainly didn't know anything of that nature."
Weaver released a statement about his written comments to the New York Times today.
"[Iseman's] comments, which had gotten back to some of us, that she had strong ties to the Commerce Committee and his staff were wrong and harmful and I so informed her and asked her to stop with these comments and to not be involved in the campaign. Nothing more and nothing less," he said.
McCain's wife also said she was disappointed with the newspaper.
"More importantly, my children and I not only trust my husband, but know that he would never do anything to not only disappoint our family, but disappoint the people of America. He's a man of great character," Cindy McCain said.
The couple smiled throughout the questioning at a Toledo hotel.
The story ran counter to the image McCain has built for himself as a crusader against congressional earmarks and a proponent of campaign finance reform, stances that have made him a hero to "good government" advocates.
"Once you're setting yourself up as a paradigm, as the example -- the best example -- of how an ethical member of Congress should behave, then you've got to know people are gunning for you if you're going to make a mistake," Melanie Sloan of Citizens for Responsibility and Ethics in Washington told CBS News correspondent Nancy Cordes.
"We think the story speaks for itself," Times executive editor Bill Keller said in a written statement Thursday. "On the timing, our policy is we publish stories when they are ready."
The "Grey Lady" appeared to be stepping into a grey area, the head of the Project for Excellence in Journalism told Cordes.
"This is an odd situation where anonymous sources aren't alleging something," Tom Rosenstiel said. "They're alleging their feelings about something."
McCain's remaining rival for the Republican nomination, former Arkansas Gov. , called McCain "a good decent honorable man" and said he accepted McCain's response.
"I've campaigned now on the same stage or platform with John McCain for 14 months. I only know him to be a man of integrity," Huckabee said in Houston. "Today he denied any of that was true. I take him at his word. For me to get into it is completely immaterial."
The published reports said McCain and Iseman each denied having a romantic relationship. Neither story asserted that there was a romantic relationship and offered no evidence that there was, reporting only that aides worried about the appearance of McCain having close ties to a lobbyist with business before the Senate Commerce Committee on which McCain served.
In late 1999, McCain twice wrote letters to the Federal Communications Commission on behalf of Florida-based Paxson Communications - which had paid Iseman as its lobbyist - urging quick consideration of a proposal to buy a television station license in Pittsburgh. At the time, Paxson's chief executive, Lowell W. "Bud" Paxson, also was a major contributor to McCain's 2000 presidential campaign.