Updated

American helicopters rescued an Afghan tribal leader who was engaged in heavy fighting with Taliban forces over the weekend, Defense Secretary Donald H. Rumsfeld said on Monday.

Hamid Karzai, a supporter of the exiled Afghan king, had entered Afghanistan to try to organize resistance to the Taliban among Pashtun leaders in Oruzgan province.

Last Thursday his party was reported to have engaged in heavy fighting with Taliban forces, but Karzai managed to avoid capture with U.S. assistance.

Rumsfeld, returning to Washington after a weekend of meetings with American allies in Uzbekistan, Tajikistan, Pakistan and India, said a U.S. helicopter extracted Karzai out of Afghanistan and back to Pakistan early Sunday morning.

Meanwhile, a small group of American military personnel is in Tajikistan assessing the possibility of using at least three bases there to expand the U.S. bombing campaign and strengthen support for Afghan opposition forces, a U.S. official said Monday.

The bases might also be useful for additional U.S. humanitarian aid flights or for establishing an overland route for such aid into Afghanistan, the official said, speaking on condition of anonymity. Tajikistan is on Afghanistan's northern border.

Rumsfeld met with Tajik President Emomali Rahmonov on Saturday but did not announce any deal.

The U.S. assessment team in Tajikistan is examining three bases: Kulyab, Khojand and Kurgan-Tyube.

In a sign of stepped-up U.S. activity in the region, a team of five U.S. military personnel landed at a new airstrip in Golbahar, Afghanistan, in the northern end of the Shomali plain "to help coordinate efforts in the war," opposition interior minister Yunis Qanoni said Monday.

He said the men arrived Sunday from Tajikistan's capital Dushanbe in a small twin-engine plane. They were expected to study the new dirt landing strip to see if it's ready to handle supplies, which would bolster northern alliance forces whose supply route through formidable mountains from Tajikistan to the north has already been snowed over.

On Sunday, U.S. aircraft dropped bombs on Taliban front lines close to four key cities in northern Afghanistan, including Mazar-e-Sharif, where the anti-Taliban northern alliance says it has launched a major offensive.

The bombing focuses on targets near Bagram, Taloqan and Konduz, in addition to Mazar-e-Sharif, the Pentagon said Sunday. The Taliban militia have forces arrayed against the northern alliance in all of those areas. Caves and tunnels suspected as hide-outs for the Taliban and the Al Qaeda terror network also were targeted by U.S. aircraft.

Mazar-e-Sharif was lost by the rebels to the Taliban in 1998. Retaking it would open a major supply route for the northern alliance from Uzbekistan and Tajikistan.

To aid the rebels, more U.S. special forces also have entered Afghanistan in the last few days, Air Force Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said on NBC's Meet the Press.

"The more teams we get on the ground, the more effectively we'll bring (opposition rebels') power to bear on the Taliban lines," Myers said.

Rumsfeld said last week he hoped to at least triple the number of special forces troops inside Afghanistan, now believed to number between 100 and 200.

The general commanding U.S. operations in Afghanistan said their purpose is "to provide an advantage to opposition leaders with whom we share a common objective."

"We synchronize our activities with their activities," Army Gen. Tommy Franks, head of the U.S. Central Command, said on ABC's This Week.

The Taliban government is weakening but still controls substantial troops that will take time to thin out and conquer, top U.S. commanders said.

"We're setting in for the long haul," Myers said. Through the winter, the United States will supply the rebels with ammunition, food and cold-weather fighting gear, he said. "We think that they have every chance of prevailing."

During his visit to India on Monday, Rumsfeld said that with more U.S. military teams on the ground in Afghanistan to direct aircraft, "The effectiveness of bombing is improving every day."

He also said he didn't think the operation would take years and that it would be completed in the least possible time.

Myers said the United States has taken out Taliban air defenses, transportation for resupplying their troops and their communications.

"They have a substantial force left, but at this point that's exactly what we expected," he said.

The generals declined to say whether it would take a major deployment of U.S. ground forces to topple the Taliban. Franks said he would not rule out the use of large numbers of troops.

Fox News' Bret Baier and the Associated Press contributed to this report.