WASHINGTON (Feb. 15) - Former New York City Mayor Rudolph Giuliani, acclaimed for his leadership after the September 11 attacks, confirmed he is running for U.S. president in 2008, eliminating any lingering doubt about his candidacy.

"Yes, I'm running," Giuliani declared twice on Wednesday night on CNN's "Larry King Live" show.

There have been doubts among Republicans about whether Giuliani was serious about a White House run in 2008.

National polls have shown Giuliani leads eight other Republicans, in part because of his steely and comforting leadership amid the chaos of the 2001 hijacked plane attacks that brought down New York's most visible landmark.

"I think I can make a difference. I believe that the country needs leadership," Giuliani said on CNN when asked what led him to purse the top political job in the United States.

Earlier this month, Giuliani filed a statement of candidacy with the Federal Election Commission establishing a committee to explore a presidential bid, but he stopped short of making a formal announcement.

Giuliani became one of the Republican  Party's most popular figures after September 11. However, he faces an uphill battle winning over conservatives who wield considerable influence in party primaries because of his stance on some social issues, including his support for gay rights and abortion rights.