President Bush urged the United Nations today to lift economic sanctions on Iraq, and warned that the United States sees a new era of warfare in which lethal technology and secret operations allow swift, precise strikes on threatening governments.

The U.N. sanctions, imposed when Iraq invaded Kuwait in 1990, restrict Iraqi oil exports and place the expenditure of oil revenue under U.N. control. Their lifting was conditioned on Saddam Hussein's destruction of all weapons of mass destruction and other actions that are now moot.

The Bush administration views the sanctions' early repeal as a crucial part of Iraq's recovery and steps toward self-government as the war wanes. The administration also sees oil as an important long-term source of funds for reconstruction. Officials said they believe the United Nations will move to lift the sanctions as early as next week.

Speaking to workers who built advanced fighter jets used in Iraq, Bush gave his first account of the practical lessons the administration learned in deposing Hussein. His description echoed remarks today by Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, who said the campaign in Iraq demonstrated "a new American way of war."

The comments by Bush and Myers seemed to indicate that the administration believes it now has armed forces capable of executing its strategic doctrine of preemption, which calls for acting first against terrorists and hostile states believed to have chemical, biological or nuclear weapons.

"By a combination of creative strategies and advanced technology, we are redefining war on our own terms," Bush said in St. Louis, with a $48 million jet parked on each side of his lectern. "In this new era of warfare, we can target a regime, not a nation."

He cited the insertion of Special Forces -- such as Delta Force, Rangers and Green Berets -- into Iraq before full-fledged fighting began. Those forces, he said, went in "to protect key infrastructure, protect the oil fields owned by the Iraqi people, secure vital bridges."

"Carefully targeted airstrikes left entire enemy divisions without arms and without organization," he said. "Precision-guided weapons fatally disrupted the regime's system of command and control." Bush said technology also "is protecting the lives of our soldiers and the lives of innocent civilians."

Myers, speaking in Washington to the Navy League, said historians tend to describe the U.S. military's favored method of warfare as an overwhelming effort of annihilation, as demonstrated by Ulysses S. Grant and William T. Sherman in the Civil War.

"By comparison, what we've done in Iraq has been dramatically different," Myers said. By waging precise and focused war, he said, the U.S. military was able to "strike directly at the heart of the regime" in Iraq and to "minimize" damage to the Iraqi infrastructure and the suffering of the country's people.

Myers also emphasized the speed with which the U.S. military now moves data. In the 1991 Persian Gulf War, he noted, the "air tasking order" -- a telephone book-sized plan for a given day's airstrikes -- had to be printed and flown to aircraft carriers by helicopters. By contrast, on April 7, when intelligence was received that Hussein and other Iraqi leaders were meeting in a Baghdad restaurant, the targeting information was conveyed to a B-1 heavy bomber, which dropped four 2,000-pound bombs on the restaurant. From the receipt of the information to the restaurant's destruction took 38 minutes, Myers said, adding, "That's really fast."

Bush, after signing a $79 billion war spending bill at the White House this morning, flew to a Boeing factory for a trip devoted largely to celebrating military successes in Iraq. "Our work is not done," he said. "The difficulties have not passed. But the regime of Saddam Hussein has passed into history."

The president tempered his remarks with comments designed to reassure Iraqis and other overseas audiences about his intentions. Bush, whose top aides have issued repeated threats to Syria in recent days, said twice that he sees war as a last resort, and said the rebuilt Iraq "must be democratic."

"We will not impose any form of government on Iraq," Bush said. "We will help Iraq to build a government of, by and for the Iraqi people."

Meanwhile today, Secretary of State Colin L. Powell said he plans to travel to Syria as part of a "very vigorous diplomatic exchange." The administration has accused Syria of developing chemical weapons and providing a haven to fleeing senior Iraqi officials.

The lifting of Iraqi sanctions would allow the administration to begin delivering on its promise that Iraqis, not outsiders, should reap the benefits of a reestablished oil ministry. "Now that Iraq is liberated, the United Nations should lift economic sanctions on that country," Bush said. It was a single sentence in a 27-minute speech, and Bush offered no elaboration about how he wanted that to occur. White House spokesman Scott McClellan told reporters on Air Force One that Bush wants Iraq to "restore a normal trading relationship with the global economy."

Baghdad's road out of sanctions is likely to be one of the first tests of whether Security Council members can work together after the bitterness that led the United States and Britain to launch the war without the imprimatur of the United Nations. The members who had squared off over Iraq, including France and the United States, have taken steps toward a rapprochement this week. But initial reaction at the United Nations was guarded. Several diplomats said they would need to know more about U.S. postwar plans before suspending or lifting sanctions.

And with Bush determined that the United Nations will play only a supporting role in redeveloping Iraq, diplomats said France, Russia and China view the sanctions as a way to keep more leverage over the process.

Congress gave Bush most of the money he asked for in the supplemental spending bill signed today, including $62 billion for the Pentagon and $8 billion for foreign aid. Congress refused to give up its prerogatives over how the money is spent. Lawmakers moved control over some reconstruction funds from the Pentagon, which Bush has put in charge, to the State Department, which typically handles foreign aid. Bush aides suggested Bush might still try to spend the money as he had originally planned.

Today's trip allowed Bush to blend his war and economic messages. He told about 1,000 Boeing workers of his pledge to "make sure anybody who's looking for a job in America can find one." Bush aides said he will face the disappointing economy head-on in coming weeks by taking a tour of the country to promote tax cuts, despite Senate resistance to his plans.

His political challenge was seen at the Boeing plant he visited in Missouri -- a state he barely won in 2000. Boeing announced last week that 240 of its manufacturing employees in St. Louis will be laid off soon.

Rep. Richard A. Gephardt (D-Mo.), a St. Louis native who is running for his party's presidential nomination, said 95,000 Missourians have lost jobs under Bush's presidency. "All that President Bush has to offer those workers and other Americans struggling in this bad economy is more unaffordable, unsustainable and patently unfair tax cuts," he said today.

Staff writers Karen DeYoung and Thomas E. Ricks contributed to this report.

U.S. Marines and Special Forces troops storm the burned Rasheed Bank in Baghdad, where about 20 men were looting the vaults. President Bush, posing with Vice President Cheney and White House interns on the south portico before leaving for St. Louis, told workers at a Boeing plant that "we are redefining war on our own terms." Girls from Providence Christian School in Dallas encounter a gust of air from the helicopter as they watch the president's departure at the White House.