Washington ? American troops will stay indefinitely in Afghanistan as local power struggles and remaining al-Qaida make it impossible to set a withdrawal deadline, defense officials say.

The U.S. troops will help train an Afghan army in addition to searching for al-Qaida fighters, and may also intervene to keep violent warlords apart.

Many analysts worry that the day American and other Western soldiers leave would be the day Afghanistan again started to disintegrate.

Troubled by threats preventing the exiled king’s return and other signs of chaos, some urge the United States to consider an even more robust role such as sending U.S. peacekeepers or supporting the expansion of a 4,500-member international security force beyond Kabul.

“Never will so much have been at stake on a modest request for 10,000 to 20,000 people,” said the United Nations human rights representative for Afghanistan, Kamal Hossain. He asked Wednesday for international peacekeepers across the country, to fill a security “vacuum.”

The Bush administration has rejected the idea of sending American peacekeepers and opposes the security force expansion.

Yet Vice President Dick Cheney said over the weekend the United States will not “walk away” from Afghanistan once the al-Qaida threat is overcome.

U.S. officials will meet next week in Geneva with other countries to try to raise money for an Afghan army, on which the Bush administration pins its hopes for a stable Afghanistan.