ASHINGTON, Sept. 20 — A top Air Force commander has flown to Saudi Arabia to oversee air attacks against Afghanistan and other potential targets in the war against terrorism, military officials said today.

American ground troops were also being sent to the region, the Army secretary, Thomas White, said today, to join two dozen bombers and support aircraft that had already begun moving within easy striking distance of Afghanistan. The Army Special Forces Command at Fort Bragg, N.C., confirmed receiving a deployment order, but declined to say how many troops were involved.

The Pentagon is planning to send combat search-and-rescue teams into former Soviet republics in Central Asia, where they would be ready to get downed pilots, two Defense Department officials said. Uzbekistan is considered most likely; President Bush called the Uzbek president, Islam A. Karimov, on Wednesday to discuss cooperating in the fight against terrorism.

Russian officials have said in recent days that former Soviet republics can decide for themselves whether to cooperate with the Americans. But the possibility of even limited American deployments there has plunged the political establishment in Moscow into a divisive debate.

Dispatching the Air Force officer, Lt. Gen. Charles F. Wald, the head of American air forces assigned to Middle East and Southwest Asia, is the latest sign of a buildup of United States military power that could be used to retaliate for last week's attacks on New York and Washington.

General Wald, who flew to Saudi Arabia on Monday with several top aides, would run the air war from a sophisticated air operations center at Prince Sultan Air Base, near Riyadh, that opened this summer. It would be the central command post not only for 175 aircraft already based in the region and involved in patrolling the no-flight zone in southern Iraq, but also for directing attacks from bases in the region against Afghanistan and other possible targets, like Iraq.

Currently, Saudi-based American fighter-bombers are restricted from attacking targets except in self defense. Today, the Saudi foreign minister, Saud al-Faisal, met with President Bush and promised full cooperation, but it is unclear whether the Saudis will lift their constraints on running bombing raids from their soil.

The administration's military campaign is extremely sensitive politically because Islamic countries are to be used as a base of operations for many of the major attacks. Not only are aircraft to be based in Saudi Arabia, the Persian Gulf states and Central Asia, but Pakistan has also been assigned a prominent role.

"It is both logistics and politics," said Teresita Schaffer, a former ranking American diplomat and expert on South Asia. "You want staging areas close to Afghanistan. The other is that the United States is trying to make it clear that Islamic states are prominently featured in this effort to avoid any suggestion that this is a war between the United States and Islam."

But this also means that there may be limits on how much force the administration deploys, she said, adding, "You have to be careful not to create such an overwhelming presence that it creates a backlash."

The Bush administration is trying to marshal as much international support as possible. The effort goes well beyond Muslim nations. Vice President Dick Cheney met today with China's foreign minister, Jiaxuan Tang.

In Brussels, Deputy Secretary of State Richard L. Armitage met with NATO ambassadors, but he offered no proof of a role by Osama bin Laden and indicated that the United States was not ready to make specific requests from allied countries for military support.

Mr. Armitage, who recently met with Russian officials in Moscow, told the ambassadors that the administration was still waiting for a response from Moscow about what cooperation the Russians might be prepared to offer and what they would not do.

Mr. Armitage indicated in his closed briefing that the Bush administration has had indirect contact with Iran, but that it was not clear what steps Tehran was prepared to take to stop its support for terrorism or help Washington in its struggle with Mr. bin Laden and the Taliban.

Iran said today that it would not allow American aircraft to fly over its territory on bombing runs over Afghanistan. "We will never allow American airplanes to use Iranian airspace to attack Afghanistan," said the Foreign Ministry spokesman, Hamid Reza Assefi.

The deployment order Secretary of Defense Donald H. Rumsfeld signed this week set forces in motion across the United States, including the lumbering B-52's from the 5th Bomb Wing at Minot Air Force Base in North Dakota and a reserve wing, the 917th, at Barksdale Air Force Base in Louisiana. B-52's would operate from a British base on Diego Garcia, an Indian Ocean island.

B-1B bombers from the 28th Bomb Wing at Ellsworth Air Force Base in South Dakota and the 34th Bomb Squadron at Mountain Home Air Force Base in Idaho were also ordered to deploy. Air Force officials said they were also readying additional aircraft, including F-15's, F- 16's and F-117's, but that by late today Mr. Rumsfeld had not ordered their deployment.

Other special forces are expected to be dispatched. Army officials declined to say which units might be sent to the region, but the Army Special Forces Command oversees an area of elite troops, including the 75th Ranger Regiment, and other airborne units like the 160th Special Operations Aviation Regiment, the 528th Special Operations Support Battalion and the 112th Special Operations Signal Battalion. The command also includes the Army's civil affairs and psychological operations units.

"We have a very strong special ops capability," Mr. White told reporters, "and I'm sure this campaign will involve them."

To carry out a mission of this scale and ambition, the United States needs cooperation of many nations, especially Pakistan.

The United States needs access to Pakistan's airspace to carry out attacks. It needs Pakistan's intelligence about Mr. bin Laden's network and the Taliban leadership. It also needs staging areas in Pakistan to carry out the sort of rapid and repeated commando operations that would be needed to capture or target Mr. bin Laden. Pakistan's military ruler, Gen. Pervez Musharraf, promised his support on Wednesday.

But Pakistan's role is a delicate matter. Too large an American presence could encourage protests and possibly destabilize the country, a frightening development for Washington given the wellspring of anti- American sentiment among Pakistani citizens and that nation's nuclear weapons ability.

Pakistan was a key base of operation when the United States funneled support for Afghan guerrillas during the Soviet occupation of Afghanistan. But there has been little military cooperation between the United States and Pakistan since 1990, one result of sanctions Washington imposed because of Pakistan's program to develop nuclear weapons.

Geography has now led the Bush administration to draw closer. Pakistan has a 1,400-mile-long border with Afghanistan, and warplanes launched from its bases are only minutes away from Mr. bin Laden's training camps and other targets.

"Pakistan is the perfect place," said one retired American general.