(Updates with fresh Obama comment)

By Randall Mikkelsen

WASHINGTON, Jan 14 (Reuters) - The U.S. government on Wednesday dismissed a new audio message from al Qaeda leader Osama bin Laden and said he was not a threat to President-elect Barack Obama's inauguration.

The tape surfaced as the United States prepares for a handover of power from President George W. Bush to Obama on Tuesday.

Bin Laden focused his message on a call for a holy war over the Israeli offensive in Gaza. He also discussed Obama and said the new U.S. president would inherit the "heavy legacy" of a long guerrilla war that would widen to more fronts, said the Internet terrorism monitor SITE Intelligence Group.

U.S. officials exhibited more of a growing confidence that bin Laden and other top al Qaeda leaders have been greatly weakened by military pressure on the Afghanistan-Pakistan border areas where they are believed to be hiding.

"It appears this tape demonstrates his isolation and continued attempts to remain relevant at a time when al Qaeda's ideology, mission, and agenda are being questioned and challenged throughout the world," White House spokesman Gordon Johndroe said. He said it also looked like a fund-raising effort.

After the Sept. 11, 2001, attacks, Bush declared that he wanted bin Laden captured dead or alive. But the al Qaeda leader has eluded a U.S. manhunt.

The inauguration is expected to draw record crowds of 1.5 million or more to the U.S. capital next week for three days of festivities. Asked if the tape represented a threat to the inauguration, FBI spokesman Richard Kolko said, "We have no specific or credible threat to the inauguration."

Tens of thousands of police and U.S. troops are planning to take part in an unprecedented inauguration security effort.

Intelligence agencies say even if al Qaeda's central leadership has been weakened, its violent intentions make the militant group dangerous.

Obama, asked about the importance of apprehending bin Laden, said he thinks the al Qaeda leader's infrastructure has to be weakened to the point where he is so pinned down that he cannot function.

"My preference obviously would be to capture or kill him. But if we have so tightened the noose that he's in a cave somewhere and can't even communicate with his operatives then we will meet our goal of protecting America," Obama said in a CBS interview.

Bin Laden's last audio tape in May also focused on Gaza, urging Muslims to help break the Israeli-led blockade of the area.

Intelligence agencies believe al Qaeda has been trying to establish a presence in Gaza, but has met resistance from the ruling Hamas Islamist group.

"Other players are more relevant to what is happening in Gaza," a U.S. counterterrorism official said. (Editing by David Alexander and Cynthia Osterman)

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