The United States, Japan, Britain and Canada pledged the bulk of the new aid at the Tokyo conference on rebuilding Afghanistan. The $50 million in new funds will be used to recruit a national army, and finance a program to disarm the populace.

At a similar conference last year, about $4.5 billion was promised, and an estimated $2 billion of that has now been spent.

Afghan President Hamid Karzai outlined a three-step disarmament process to the delegates, saying that widespread gun ownership and a failure to disband the nation's private armies were major challenges to peace. He said they could threaten the general election slated for next year, the first in the country's history.

He also said that remnants of the ousted Taleban government and al-Qaida terrorist network are still hiding in remote areas of the mountainous nation.

"My own perception is that they are already doing the best that they can to hurt us," he said. "They are defeated, and they want to show they can do something."

Mr. Karzai laid out his government's recent triumphs for reporters, saying millions of refugees were returning, children were back in school and health care services have improved since the fall of the Taleban in December 2001.

He said his government had overseen a smooth transition to a new Afghan currency.

"We adopted a policy of giving a new currency to the country, a new Afghan currency, rather than dollarization," Mr. Karzai said. "We decided, and in two or three months, we printed the new currency, and in three months' time we implemented the change to a new currency, and it succeeded. The new currency is now available all over the country."

Ambassador David Johnson, the U.S. coordinator for Afghanistan who also attended the conference, said U.S. troops will stay in the country as long as they are needed. He said the United States might offer hundreds-of-millions of dollars in additional funds, if Congress approves it.

Washington has spent more than half-a-billion dollars on humanitarian aid projects in Afghanistan since the defeat of the Taleban. The World Bank and other groups say that more than two decades of war have left the country in need of 15 billion dollars to rebuild its ruined infrastructure.