WASHINGTON - With many governments offering to help the United States "in any way possible" against the terrorist organization and its backers that were behind the attacks last week, senior U.S. officials said they are rushing to negotiate military and other agreements "that put those promises in writing -- before anyone changes their mind."

While declining to say which governments they are negotiating with, senior officials said they are seeking agreements dealing with bases and forces. They also want legally binding commitments for military, intelligence and other assistance from nations in the region around Afghanistan, where Saudi exile Osama bin Laden, the "prime suspect" according to U.S. President Bush, is believed to be hiding.

Senior U.S. officials also are preparing for two key meetings Wednesday with Russian officials: Secretary of State Colin Powell with his counterpart, Foreign Minister Igor Ivanov, and Deputy Secretary of State Richard Armitage with senior Russian officials in Moscow.

Officials said the Armitage mission will be to sound out how much military and intelligence cooperation is possible with the Russians. He will ask whether U.S. forces can use Russian airspace and the airspace of former Soviet republics such as Uzbekistan or Tajikistan. The subject of whether ground forces could pass through the northern neighbors of Afghanistan "may also come up," officials said.

Pakistan has agreed to allow U.S. military overflights of its territory if necessary, but has not been asked to accept ground forces, officials say. Uzbekistan has expressed willingness to help a possible military effort, while Tajikistan has said it will not, according to U.S. officials.

In Washington, officials said, the United States will stress to Ivanov that it seeks closer cooperation with the Russians on protecting nuclear, chemical and biological materials. U.S. officials also want from Russia any information it might have about terrorist groups or states of concern, including Iraq, Iran and North Korea.

Undersecretary of State John Bolton made that point in preliminary talks in Moscow over the weekend, officials said. Though the United States supplies money and security equipment to help secure Russian weapons, since President Vladimir Putin replaced Boris Yeltsin, Russian officials have become less willing to allow U.S. experts access to facilities.

Concerning possible Russian help against terrorists in Afghanistan -- and possibly the Taliban government there -- a senior U.S. official said he expects "a good deal of cooperation," though he noted "they are goosey about us wandering around in their back yard."

Russian officials have expressed concerns about a possible flood of refugees, destabilization of the Central Asian region and a possible increase in U.S. influence in the region.