ASHINGTON, Sept. 21 ・The Bush administration moved today to reward Pakistan, its new partner in the war on terrorism, while European allies signaled their support by endorsing an American military response to the attacks on New York and Washington.

The administration told Congress today that it would soon waive economic sanctions against Pakistan and India that were imposed after they tested nuclear weapons in 1998.

Officials said the action was a reward for Pakistan's willingness to provide intelligence and logistical support for an American military response to the attacks.

The sanctions, which bar economic and military assistance to Pakistan and India, could be waived as soon as next week, a senior administration official said.

The administration announced its decision as countries around the world rallied to President Bush's appeal to join the United States in the fight against terrorism.

At a special meeting of the 15- nation European Union in Brussels, leaders endorsed "an American riposte" to the attacks and approved proposals for Europe-wide arrest warrants and stronger laws against money laundering.

Suspects linked to the attacks were detained in Britain, and Germany issued arrest warrants for two others.

The European Union leaders issued a declaration saying: "An American riposte is legitimate. According to their respective means, the member states of the Union are ready to commit themselves to such action."

Belgium's prime minister, Guy Verhofstadt, said European states were now prepared to join military actions "against states harboring or supporting terrorists."

Such military action became more likely ・and perhaps more imminent ・after the Taliban, the militant Islamic rulers of Afghanistan, today rejected any possibility of delivering the prime suspect, Osama bin Laden, a Saudi fugitive with bases in Afghanistan.

The administration also gained support from China today. Mr. Bush met with China's foreign minister, Tang Jiaxuan, who "reiterated his determination to fight terrorism," said Sean McCormack, a White House spokesman. Mr. Tang told Secretary of State Colin L. Powell earlier in the day that China would share intelligence on terrorist groups.

Next week Prime Minister Jean Chr騁ien of Canada and Prime Minister Junichiro Koizumi of Japan are to meet with President Bush at the White House.

Before the terrorist attacks last week, the administration was enthusiastically planning to waive sanctions against India. But it was hesitant about lightening the penalties against Pakistan. That hesitancy changed after the Pakistani leader, Gen. Pervez Musharraf, yielded to Washington's demands to allow his country to become a base for attacks against the prime terrorist suspect, Osama bin Laden, and the Taliban government in Afghanistan.

In another show of support, Senator Joseph R. Biden Jr., chairman of the Foreign Relations Committee, who had opposed the waiving of the sanctions against Pakistan, changed his mind after Pakistan said it would support the antiterrorist campaign.

Pakistani officials have indicated that they had no problem with sanctions being waived against its archenemy India. Before the terrorist attacks, Pakistan was concerned that the administration might move to lift sanctions against India.

The administration was also discussing a large American aid package for Pakistan, a senior official said. "We're looking at a big number," the official said. "How much in cash and how much in debt relief is still being debated." The Office of Management and Budget had yet to make decisions on the size of the financial aid, the official said.

On the sanctions issue, the under secretary of state for political affairs, Marc Grossman, informed congressional leaders that the administration wanted to exercise its right to waive the trade curbs. He found little opposition to the idea, which had been common knowledge for some days.

Indeed, a senior administration official said many members feared that General Musharraf's regime would collapse because of the opposition by radical Islamic leaders to the new alliance with the United States.

At the moment General Musharraf seems to have his people's support. Pro-Taliban rallies have been routine and mostly mild. But whether that support would last if American bombs hit Afghanistan, a Muslim neighbor, remains to be seen. "There was a widespread feeling on the Hill that if Pakistan supports us, we should support them," the official said.

The sentiment contrasts sharply to attitudes during the Clinton administration when the State Department vigorously opposed waiving sanctions against either Pakistan or India because they both possessed nuclear weapons.

The crucial measure to be waived is known as the Glenn amendment, named after former Senator John Glenn, Democrat of Ohio, who pushed the law through after the tit- for-tat nuclear tests by India and then Pakistan in 1998. The amendment limits the ability of the United States to provide assistance.

United States military assistance to Pakistan was already barred under a 1990 amendment proposed by former Senator Larry Pressler, Republican of North Dakota, in an attempt to stop Pakistan acquiring nuclear know-how. An earlier 1978 sanction, named after Senator Stuart Symington, Democrat of Missouri, was also aimed at preventing the ability of Pakistan to develop nuclear weapons. Both these earlier sanctions would be waived as well, an administration official said.

The quick moves to waive the sanctions coincided with plans announced this week by the International Monetary Fund to go ahead with a sizable loan for Pakistan.

Successive governments in Pakistan, plagued by corruption, have had trouble meeting economic and financial goals set by the I.M.F. But the managing director of the agency, Horst Kler, said this week that under a new finance minister, Pakistan had started to perform better.

In Brussels, the mood among European leaders was resolute. The leaders backed proposals ranging from tougher law enforcement to more stringent financial laws, measures they had rebuffed or dithered about in the past. If the proposals are adopted, judges in Europe would be able to issue arrest and search warrants enforceable across the continent. Extradition procedures would be eliminated.

All 15 nations of the European Union would adopt the same definition of "terrorist crimes" and assign them higher priorities. The proposal envisions a Europe-wide agreement on prison sentences, with life sentences the maximum. The death penalty is outlawed in the 15 countries.

If the proposals all pass, a prosecutor in Italy, for example, could swear out a warrant for a British citizen and hand it over to the British police, ordering them to make the arrest and immediately bring the suspect before an Italian judge.

Currently, the Italian prosecutor would have to explain his case to a British prosecutor, confirm that British and Italian law match closely enough to make the act a crime in both countries, wait for a British prosecutor to get a warrant from a British court and make the arrest, and then file an extradition request.

The changes will be incorporated in a detailed bill to be presented to a conference of European Union justice and home affairs ministers scheduled for Dec. 6. If the proposal passes then, all 15 member countries would try to bring their laws into line.