President Bush honored American independence and the sacrifices of U.S. fighting men and women Tuesday with a reminder that victory in Iraq will require "more tough fighting" and "more sacrifice."

Marking the July Fourth holiday with a visit to Fort Bragg, N.C., Bush said the enemy in Iraq has become more vulnerable as a result of persistent efforts by U.S. and Iraqi troops.

"On this day when we give thanks for our freedom, we also give thanks to the men and women who make our freedom possible," Bush said. "You are serving our country at a time when our country needs you. And because of your courage, every day is Independence Day in America."

In his remarks before a crowd of 3,500 soldiers and their families, the president recognized Fort Bragg's heavy sacrifice in the War on Terror. That base has lost 115 soldiers in Afghanistan and Iraq. He pledged the losses of American military service personnel will not have been for nothing.

"I will make you this promise, I'm not going to allow the sacrifice of 2,527 troops who have died in Iraq to be in vain," Bush said to the crowd of uniformed troops, who responded with a chorus of "Hooah."

The commander-in-chief met with members of the 82nd Airborne and the U.S. Army Special Operations Command. Among those he met was a helicopter pilot from the 160th Special Operations Aviation Regiment who personally transported deposed dictator Saddam Hussein to Baghdad from the spider hole where he was captured.

"Good job," Bush told the pilot.

Bush ate lunch with members of the 2nd Battalion, 3rd Brigade Combat Team during the base's Independence Day celebration. After the meal, the troops presented a cake and sang "Happy Birthday" to Bush, who turns 60 on Thursday.

During his speech, the president did not discuss troop levels, and refused once more to set a timetable for U.S. troop withdrawal from Iraq.

"We're not going to set an artificial timetable," the commander-in-chief said, calling such an idea a "terrible mistake." To do so, he said, "would breathe new life into [the enemy's] cause" and undermine the new Iraqi government and the morale of U.S. troops.

The president spoke at length about the recent killing of Al Qaeda in Iraq leader Abu Musab al-Zarqawi, saying that coalition and Iraqi forces have launched more than 190 raids on targets across Iraq, captured more than 700 enemy operatives and killed some 60 more. In the process, caches of weapons and additional intelligence have been gained.

"We get all kinds of evidence when we raid these safehouses about their concerns. They bemoan the fact that we're keeping the pressure on them. They see the successes that we're having in training. They know we're damaging their cause. This moment when the terrorists are suffering from the weight of successive blows is not the time to call retreat. We will stay, we will fight, and we will prevail," Bush said.

"At this moment of vulnerability for the enemy," he said, "we will continue to strike their network. We will disrupt their operations, and we will bring their leaders to justice."

But back in Iraq, terrorists seem unwilling to give up on fomenting chaos. Gunmen in camouflaged uniforms kidnapped Iraq's deputy electricity minister, Raed al-Hares, and 11 of his bodyguards in eastern Baghdad on Tuesday. The kidnapping occurred three days after gunmen seized a Sunni female legislator in east Baghdad; she and seven bodyguards are still missing.

Elsewhere, Iraq's justice minister demanded the U.N. Security Council ensure that U.S. troops are punished for allegedly raping and murdering a young Iraqi woman and executing her relatives. The March 12 attack was among the worst in a series of cases of U.S. troops accused of killing and abusing Iraqi civilians.

In Afghanistan, U.S.-led troops are facing a recent upsurge of violence from the Taliban in the south. A group of Afghan laborers were killed on their way to a U.S. military base in eastern Afghanistan, and at least 10 people were wounded when two bombs rocked Kabul.

Back in Washington, D.C., Bush planned to watch the Fourth of July national fireworks display from the White House, where he and his family will celebrate his 60th birthday on Thursday.

Among the estimated 150 people who were expected for the Tuesday night fireworks show were Bush friends Brad Freeman, Joe O'Neill, Mike Weiss and Charles Younger, who rode with him to Fort Bragg aboard Air Force One.

FOX News' James Rosen and The Associated Press contributed to this report.