Defense Secretary Donald H. Rumsfeld said today that 8,000 U.S. forces in Afghanistan have ended major combat operations and will shift their focus to stabilizing and rebuilding the country.

Lt. Gen. Dan K. McNeill, the top U.S. commander in Afghanistan, said he doubted that the size of the U.S. force here could be reduced until the summer of 2004, when it will have finished training and equipping between 9,000 and 12,000 soldiers in a new Afghan national army. About 4,500 Afghans have been trained to date.

"After that it probably can be smaller, because I think the Afghans can take over most of the controls," McNeill said. "I think there's still going to be combat operations. There are some areas [along the Pakistani border] that are going to be a little bit messy for some time to come yet. But in most of the country you'll find more security than has existed here in decades."

Rumsfeld, who arrived in Kabul after a five-country tour of the Persian Gulf region, announced the transition from major combat to stability operations in Afghanistan as President Bush made a similar declaration aboard the USS Abraham Lincoln with respect to Iraq.

But Rumsfeld told reporters after meetings with Afghan President Hamid Karzai that there was no comparing the two conflicts. In Afghanistan, he said, a relatively small U.S. force has been engaged in rooting out the remnants of al Qaeda since the Taliban fell in late 2001.

In Iraq, by contrast, a force of 135,000 U.S. and British troops had been assembled to fight a conventional army, he said, and has been capable of moving to postwar operations much more quickly.

Rumsfeld underscored that smaller-scale combat operations will continue in Afghanistan against pockets of Taliban and al Qaeda resistance. But he said he hoped the beginning of a more deliberate reconstruction phase will encourage other countries and nongovernmental organizations to step forward and help rebuild the country. U.S. forces will help staff eight reconstruction teams by the end of the year in important regional cities, he said.

Karzai, who addressed reporters with Rumsfeld, denied that he was incapable of traveling freely throughout Afghanistan out of fear for his safety. "With regard to my movements in Afghanistan, I think I can move much freer than lots of other heads of state can move in their countries," he said.

Karzai insisted that his government was making slow but gradual progress in asserting central authority over the regional warlords who hold sway in some provinces by virtue of strong ethnic ties and sizable local militias.

"Afghanistan has gone through 30 years of anarchy, war and instability," Karzai said. "The consequences of that is a true weakening of the institutions that govern any state, not just Afghanistan. Politically, the country is very, very strongly cohesive. But we have to give this nation the institutions that will provide it with the administration that is needed."

Since toppling the Taliban and dislodging Osama bin Laden and his al Qaeda network, the Bush administration has maintained about 11,000 U.S. and allied combat forces here. They are aided by a 5,500-soldier International Security Assistance Force (ISAF), now headed by Germany. The ISAF operates only in the area of Kabul, the capital.

With major combat operations still going in the first half of 2002, the administration opposed calls to expand the ISAF and station the peacekeeping force throughout the country. Since then, the administration has modified its position and supported an expansion of ISAF, which will come under NATO command this summer.

So far no countries have stepped forward to contribute additional peacekeepers, defense officials said.

During his four-hour stopover in Kabul, Rumsfeld toured a training facility where U.S. Special Forces and private contractors are putting the new Afghan troops through a 10-week infantry training course. McNeill said there was a problem initially with Afghans not completing the training. But he said the situation has improved "dramatically" since Karzai's government has become more involved in the recruiting process and more Pashtuns, the dominant ethnic group, have volunteered for service.

In addition to training the new Afghan force, the Pentagon has also backed the creation of provincial reconstruction teams made up of U.S. and allied military and civilian authorities. Currently, these teams are functioning in Gardez, Bamian, and Kunduz. By the end of the year, five more teams will be established in Mazar-e Sharif, Kandahar, Jalalabad, Herat and Parwan, according to a statement released by the U.S. Embassy here.