The Pentagon has directed the Army to study alternatives, such as transporting the weapons from the depot and its sister plant in Colorado, in an effort to meet a 2012 treaty deadline for destruction of the stockpile.

The closest incineration plant is in Anniston, Ala., about 380 miles from Richmond.

The Army said it had yet to begin a review of the Pentagon request and will also consider alternatives to shuffling lethal weapons between sites.

"It is premature at this time to comment on the content of the evaluations," Michael A. Parker, who directs the Army Chemical Materials Agency, said in a statement.

But an opponent accused the Pentagon of violating years of promises by even raising the possibility of moving chemical weapons.

The Army decided in the late 1980s to dispose of the weapons at the storage sites.

It rejected shipping by road or air as too dangerous and said weapons sent to other sites would be "much more vulnerable to sabotage or terrorism" than those guarded by the Army at storage sites.

In Colorado, U.S. Sens. Wayne Allard and Ken Salazar said they received assurances Tuesday that the Pentagon would not attempt to incinerate or move chemical weapons stored at the Pueblo Chemical Depot.

"Obviously," said Craig Williams, director of the Berea-based Chemical Weapons Working Group, "Pentagon representatives had no problem misleading Senators Allard and Salazar yesterday, just as they have had no problem misleading citizens and elected officials for more than 20 years.

"There is absolutely no basis for anyone, at any site, at any level of government to believe or have confidence in any commitments made by these people."