(CNN) -- New York City Mayor Michael Bloomberg, who has publicly flirted with the idea of a run for the White House as an independent, said he will not run for president.
New York City Mayor Michael Bloomberg wrote in a New York Times op-ed that he will not run for president.
The current presidential candidates were showing signs of the "independent leadership" he believes the nation needs, Bloomberg said during a press conference Thursday.
He also said he would support the candidate who "does the right things" and helps get "the ideologues out of the decision-making process."
Bloomberg pressed the candidates to show voters "concrete plans" for the problems facing the nation that include details on how those plans will pass Congress and how the programs will be funded.
"We all have a responsibility to help move our country forward," he said. "It's time for people to move away from just saying 'I am for motherhood and apple pie.'"
Bloomberg, a former Republican who become an independent while in office, announced his decision in an op-ed posted on the New York Times Web site Wednesday night and published in the paper's Thursday edition.
"I listened carefully to those who encouraged me to run, but I am not -- and will not be -- a candidate for president," Bloomberg wrote.
The 66-year-old billionaire had publicly repeated that he was not a candidate for president in recent months, while leaving open the option that he could become one.
"Bloomberg only wanted to run if he thought he could win, and I think he sees very little room," said Mark Halperin, a senior editor for Time magazine.
A source close to the mayor told CNN in January that he had collected poll data assessing his chances and that the mayor was expected to make his final decision by March.
Bloomberg mentioned in his editorial that he would work to "steer the national conversation away from partisanship and toward unity; away from ideology and toward common sense; away from sound bites and toward substance."
Bloomberg, a former Democrat who won the mayor's office as a Republican, would have been on a strict timetable to start collecting signatures to get on the ballot, a process that varies from state to state.
At a summit designed to bridge the divide between Democrats and Republicans, Bloomberg said in January partisanship is limiting the nation's progress.
"People have stopped working together, government is dysfunctional, there's no collaborating and congeniality," he said. "America is being held back."
In the opinion piece, Bloomberg said he's hopeful that the current Democratic and Republican campaigns will address an independent approach to governing.
"I have watched this campaign unfold, and I am hopeful that the current campaigns can rise to the challenge by offering truly independent leadership," he said. "The most productive role that I can serve is to push them forward, by using the means at my disposal to promote a real and honest debate."
Bloomberg could also play a role in the election if he makes an endorsement. He is good friends with McCain, and he also likes Obama, Halperin said.
"If a candidate takes an independent, nonpartisan approach -- and embraces practical solutions that challenge party orthodoxy -- I'll join others in helping that candidate win the White House," he said in the opinion piece.
Bloomberg was elected mayor of New York in 2001, two months after the September 11, 2001, attacks on the World Trade Center. He was re-elected in 2005.
A native of Medford, Massachusetts, with an MBA from Harvard Business School, Bloomberg became a billionaire, first working with Wall Street securities bank Salomon Brothers then as founder of Bloomberg LP, a financial news and information service. E-mail to a friend
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