By Tabassum Zakaria

NEW YORK (Reuters) - President George W. Bush made a pilgrimage to New York's Ground Zero on Sunday on the eve of the fifth anniversary of the Sept. 11 attacks and said he would never forget the lessons of that day.

The somber Bush and his wife, Laura, laid wreaths at Ground Zero, attended a prayer service nearby with families who lost loved ones, then shook hands with firefighters at a firehouse near where the World Trade Center's twin towers had stood.

"I vowed that I'm never going to forget the lessons of that day," Bush told reporters before a memorial on the side of the firehouse of Ladder Co. 10, Engine Co. 10.

"There's still an enemy out there that would like to inflict the same kind of damage again," Bush said. "So tomorrow is also a day of renewing resolve."

Bush's approval ratings soared and his presidency was transformed after he stood in the ruins of the World Trade Center days after the 2001 attacks that killed nearly 3,000 people and sought to rally the country by shouting into a bullhorn. But his ratings slid as U.S. casualties in Iraq rose, and polls show many Americans now doubt his security policies.

Coming two months ahead of elections in which Democrats hope to wrest control of Congress from Bush's Republicans, the anniversary has triggered a partisan battle over whether the country is vulnerable to another attack and whether the Iraq war is a distraction from efforts to eliminate al Qaeda.

Outside the World Trade Center site, several dozen people held up banners and shouted, "Arrest Bush Now," "Bring the Troops Home" and "Stop Exploiting 9/11."

"This visit is another political ploy for Bush to try to sound like he is strong on security when our country is much less safe," said 77-year-old protester Ann Muyskens.

Under gray skies, the Bushes, New York Mayor Michael Bloomberg, former Mayor Rudolph Giuliani, and state Gov. George Pataki had walked into the flag-bedecked Ground Zero site.

The Bushes dropped wreaths into two dark pools of water in the footprints of the north and south towers, which collapsed in 2001 after hijacked airplanes smashed into them. They bowed their heads as bagpipes played "America the Beautiful."

"HELLUVA JOB"

In a two-day tour of all three Sept 11. crash sites -- the World Trade Center, Pentagon and the field in Shanksville, Pennsylvania, where United Flight 93 crashed -- Bush will strive to put aside partisan acrimony, if only temporarily.

Thousands of people, many dressed in white T-shirts, walked from the Washington Monument to the crash site at the Pentagon for a memorial service and concert to honor those killed there on Sept. 11.

Vice President Dick Cheney and other top administration officials sought on Sunday to promote what they say is progress in protecting America against another attack.

Democrats countered the administration had used the attacks for political gain, underlining the bitter divisions that have emerged since the attacks on New York and Washington united the nation in grief.

Cheney told NBC's "Meet the Press" that five years with no repeat attacks in the United States proved the government had succeeded in disrupting al Qaeda.

"We've done a helluva job here at home in terms of homeland security," Cheney said.

Al Qaeda marked the anniversary by posting video footage of Osama bin Laden exhorting the attackers to be patient in their preparations and to steel themselves for "martyrdom."

In the tape, parts of which were aired by Al Jazeera television on Thursday, one of the men who flew the second aircraft into the World Trade Center issued a warning to the United States.

"I say to America if it wants its armies and people to be safe then, it must withdraw all its forces from Muslim land ... or else it should prepare coffins and big graves," said Hamza al-Ghamdi, who posed next to a miniature aircraft.

(Additional reporting by Thomas Ferraro in Washington and Christine Kearney in New York)