Already three years on the drawing board, a U.S.-Russian center aimed at avoiding accidental missile launches won't open for at least another year, a Pentagon official said Wednesday.

Plans to convert a building on the outskirts of Moscow into a joint early warning center are hung up on Russia's insistence the United States pay taxes on the equipment it takes into the country and accept liability for the construction, said Philip Jamison, deputy director of the Defense Department office on international security.

"It essentially boils down to diplomatic issues," he told a seminar at the Cato Institute. Jamison said the center could be open for testing at the end of 2002 if those matters can be resolved within the next two months.

Though the issues seem small in relation to the hoped-for benefits of the center -- that is, to prevent accidental nuclear catastrophe -- U.S. officials have said they don't want to set a precedent on taxes and other matters that could create problems elsewhere.

When plans for the center were announced in September 1998, then-President Clinton said it was aimed at averting "nuclear war by mistake." Officials said that because Russia doesn't have money to properly maintain its warning system, it could mistakenly think the United States had launched a nuclear missile -- and retaliate.

In 1995, Russia's military briefly mistook a scientific rocket from Norway for a U.S. intercontinental ballistic missile. Officials say Moscow's constellation of warning satellites has seriously decayed since then, with some out of orbit and believed not functioning.

The new center is to be staffed jointly by three dozen U.S. and Russian officers. The system planned at the center would collect information from the warning systems of each country and share it, reporting such things as time and location of any missile launches, the missile type, direction it was heading and place it would hit.

The center was to open months ago. Besides the tax and liability problems, the project lost momentum late last year as Clinton was leaving office and early this year as President Bush was just coming in and reviewing U.S. policy toward Moscow.

Another panelist, Geoffrey E. Forden of Massachusetts Institute of Technology, argued the center won't work anyway because Russian officers won't have confidence in it. In times of tensions between the two countries, Forden said, Moscow will not rely on information received from the United States.

Washington should help Russia repair its own warning system instead, he said.

U.S.-Russia talks recently been dominated by Washington's plan to create a missile defense system.

The plan would require amending or breaking a 1972 Anti-Ballistic Missile Treaty. But Moscow sees the treaty as a cornerstone of world stability and fiercely objects to the U.S. plan.

The third panelist, Hank Cooper of the private missile defense research group High Frontier, suggested Washington could win concessions on the system it wants by helping Russian with its warning system.

"I wouldn't just go off and buy them a warning system," Cooper said. "Our demand ought to be that we do it in the context of a global defense ... in the context of building a system that we want."