"Now is not my time," he said at the Statehouse news conference. "I have a commitment to New Jersey that I simply will not abandon."
Christie had been discussed as a presidential contender since shortly after he took office last year, but he has denied his interest in a series of definitive, and often colorful, statements. At one point, he threatened to commit suicide to prove he was not running.
Rumors about a candidacy intensified 10 days ago after news reports, based on anonymous sources, that Christie was reconsidering a run given the weak presidential field and aggressive courting from deep-pocketed Republicans.
Speculation was further fueled days later when Christie gave a well-received speech at the Reagan Presidential Library in California in which he criticized President Obama and, indirectly, presidential candidate Rick Perry.
On Tuesday, at the most-well-attended news briefing of his term, Christie acknowledged for the first time that he and his wife, Mary Pat, had discussed his jumping into the race.
"Three weeks ago, Mary Pat woke me up at 6 in the morning and said, 'If you want to run, go for it, go for it, and don't worry about me and the kids. We'll be fine,' " he said.
Christie began to reconsider, he said, after receiving encouragement not just from powerful people. He cited a Nebraska farmer who FedEx-ed a letter to Christie's children and told them that "they would be remembered in the history books as the people who helped change the course of a country's history" if they persuaded their father to run.
"When you have serious people from across the spectrum - not to mention from all across the country - passionately calling on you to do something as consequential as running for president of the United States, I felt an obligation to honestly consider their advice," Christie said.
