Updated

American soldiers are in Afghanistan advising anti-Taliban forces and helping guide bombs to their targets, Defense Secretary Donald H. Rumsfeld said as he prepared to visit the region this weekend.

Rumsfeld will travel to Moscow to meet Russian Defense Minister Sergei Ivanov, then visit leaders of several countries surrounding Afghanistan to shore up efforts in the war against terrorism, the Pentagon said Wednesday.

"The initial reason for the trip is to go to Moscow and see Ivanov to talk about the war on terrorism, to talk about the [Anti-Ballistic Missile Treaty] to talk about the broader way forward with Russia," said Pentagon spokeswoman Victoria Clarke.

She didn't name the other nations he would visit on the trip, which begins Friday.

And the Pentagon has informed the White House that Rumsfeld intends to call up more than the 50,000 reserve troops he initially thought would be the most needed for the campaign in Afghanistan and homeland defense, she said. She didn't give a new number, but under an order signed by President Bush shortly after the Sept. 11 terrorist attack, up to 1 million reservists could be activated.

Meanwhile, warplanes launched heavy bombing raids Wednesday on Taliban front line positions north of the Afghan capital. Witnesses said it was some of the heaviest bombing of the front line yet, with at least 11 bombs striking Wednesday morning.

Rumsfeld acknowledged for the first time Tuesday that U.S. special forces are in Afghanistan.

"Because they are there now, the effort has improved in its effectiveness," he said of targeting in the air campaign. Target information supplied by opposition forces has not been exact enough, officials have said.

Rumsfeld said a "very modest" number of U.S. forces -- less than 100 -- are in northern Afghanistan, working with specific units of the loose anti-Taliban coalition known as the northern alliance. He said other U.S. forces had been "in and out" of southern Afghanistan to work with Taliban opponents there.

Rumsfeld did not say which U.S. troops are in Afghanistan or how long they have been there, but from his description of their missions it seemed likely they included Army Special Forces, commonly called Green Berets.

Senate Majority Leader Tom Daschle, D-S.D., said after meeting with President Bush on Wednesday that congressional leaders are satisfied with the military action so far.

"There may be a need for additional efforts on the ground and if that's necessary I'm sure the president will brief Congress on the importance of doing it," Daschle said. "We're prepared to work with him."

Rear Adm. John Stufflebeem said the American ground forces had been in Afghanistan for days, not weeks, and were there because northern alliance officials asked for them.

The Bush administration has come under increasing criticism in recent days for not doing more to destroy the Taliban militia and assist the northern alliance.

That alliance, with modest U.S. help, is hoping to win control of the crossroads city of Mazar-e-Sharif.

Rumsfeld said about 80 percent of Tuesday's planned attacks were against Taliban forces in the field. That's meant to help clear the way for advances by the northern alliance, which also is facing off against Taliban troops near Bagram, about 25 miles north of Kabul.

Rumsfeld said President Bush had not ruled out committing ground troops in numbers comparable to the 1991 Gulf War, when hundreds of thousands were deployed.