Vice President Dick Cheney argued forcefully Tuesday against an early withdrawal of U.S. forces from Iraq, saying that would be "unwise in the extreme" and increase the risk of terrorist attacks in the United States and other nations.

"On this both Republicans and Democrats should be able to agree: The only way the terrorists could win is if we lose our nerve and abandon our mission," Cheney said at this military base in northern New York, where the Army's 10th Mountain Division and the New York Army National Guard's 42nd Infantry Division gathered for a rally.

"I realize some have advocated a sudden withdrawal of our forces. This would be unwise in the extreme -- a victory for terrorists, bad for the Iraqi people and bad for the United States," Cheney said to cheers from the troops. "To leave that country before the job is done would be to hand over Iraq to car-bombers and assassins."

The Troy, N.Y.-based 42nd Infantry, whose commander oversaw a task force of 24,000 troops in north-central Iraq, had about 3,500 guardsmen return home in November.

The vice president's appearances, which include a rally and a sit-down with troops, was part of a series of speeches by top administration officials intended to spell out U.S. goals in Iraq more clearly in the run-up to Iraq's Dec. 15 elections to pick a permanent government.

They come as polls show President Bush's approval rating at the lowest of his presidency: 37 percent in a recent AP-Ipsos poll, with a majority of Americans now saying the war was a mistake.

One of the administration's harshest critics in recent weeks has been Rep. John Murtha, D-Pa., a longtime hawk on military matters who now wants U.S. troops to pull out of Iraq. Murtha charged Tuesday that the administration was trying to justify the U.S. presence in Iraq by saying it was necessary to fight terrorism, when in reality the problem was insurgents rebelling against the U.S. presence and U.S.-backed government.

"When you fight an insurgency, you have to win the hearts and minds of the (Iraqi) people, and we've lost the hearts and minds of the people," Murtha said in an interview on NBC. Once the U.S. withdraws from Iraq, he said, the Iraqis themselves would take care of terrorist groups.

"Our military has done everything they could do," Murtha said. "The Iraqis themselves have to take care of Al Qaeda. ... We'll be better off if we redeploy outside of Iraq and go back in for something that affects our allies in the region or our national security."

Cheney's words to the troops were not as biting as two speeches he made late last month, one to a Republican audience and the other to the conservative American Enterprise Institute, in which he lambasted Democratic lawmakers who voted to authorize the war in October 2002 and are now among the most outspoken war critics.

The vice president called them "dishonest and reprehensible" and "corrupt and shameless."

On Tuesday, he praised Democratic Sen. Joe Lieberman of Connecticut for supporting the U.S. mission, and underscored divisions within the minority party.

"Some have suggested by liberating Iraq from Saddam Hussein we simply stirred up a hornet's nest. They overlook a fundamental fact: We were not in Iraq in September 2001 and the terrorists hit us anyway."

If the U.S. suddenly pulled out of Iraq, "that nation would return to the rule of tyrants, become a massive source of instability in the Middle East and be a staging area for ever greater attacks against America and other civilized nations," the vice president said.

Cheney was one of the administration's most forceful advocates of toppling Saddam Hussein's regime before the war that has now lasted 2 1/2 years. And he has lately been one of the most vocal defenders of Bush's appeals to stay the course in Iraq.

The latest round of speeches on Iraq began last Wednesday with Bush's address to the U.S. Naval Academy in Annapolis, Md., in which he detailed progress but gave no departure date, and the White House release of a 35-page document titled "National Strategy for Victory in Iraq."

Defense Secretary Donald H. Rumsfeld delivered an installment Monday in a speech to the Johns Hopkins School of Advanced International Studies. He criticized the news media's coverage of the war, claiming it emphasized negative stories, and said Iraqis themselves are more optimistic about their country.

About 3,100 troops from Fort Drum are currently serving in Iraq.