While he mentioned no country by name, Defense Minister Sergei Ivanov's comments reflected persistent wariness over U.S. intentions, despite arms control deals and increased cooperation between the Cold War foes since the 1991 collapse of the Soviet Union.

"Russia's position on this question has not changed for decades: We are categorically against the militarization of space," the Interfax news agency quoted Ivanov as saying during a visit to the Baikonur space facility in Kazakhstan.

"If some state begins to realize such plans, then we doubtless will take adequate retaliatory measures," ITAR-Tass quoted Ivanov as saying.

The comments came as the Bush administration reviews the U.S. space policy doctrine. White House spokesman Scott McClellan said last month the policy review was not considering the militarization of space. But he said U.S. satellites must be protected against new threats that he said have emerged since Washington's space doctrine was last reviewed in 1996.

Moscow's concerns about space-based weapons go back to the Soviet-era space race and President Ronald Reagan's 1980s plans for a "Star Wars" missile defense system.

In 2002, after the United States withdrew from the 1972 Anti-Ballistic Missile Treaty, China and Russia submitted a proposal for a new ban on weapons in outer space.

But the United States has said it sees no need for any new space arms control agreements. It is party to the 1967 Outer Space Treaty, which prohibits stationing weapons of mass destruction in space.

Ivanov's comment about negotiating controls over tactical nuclear weapons was also a clear reference to the United States, which has such arms in Europe.

"We are prepared to start talks about tactical nuclear weapons only when all countries possessing them keep these weapons on their own territory," Interfax and ITAR-Tass quoted Ivanov as saying. "Russia stores its tactical nuclear weapons on its own territory, which cannot be said about other countries."

The news agencies said Ivanov was responding to calls by former Sen. Sam Nunn for a Russian-American agreement providing for accountability of each other's tactical nuclear stockpiles, which have not been addressed by a series of treaties reducing strategic nuclear arms.

Nunn, an architect of a major program to secure and destroy nuclear weapons and materials in the former Soviet Union, has called for "transparent accountability" of tactical weapons as a safeguard against nuclear terrorism.

Russia wants to keep its tactical nuclear weapons — and to keep their number secret — to compensate for inferiority in conventional weapons, said Alexander Pikayev, a nuclear expert with the Committee of Scientists for Global Security.

The Bush administration has not publicly called for an agreement on accountability and control over tactical nuclear weapons, which do not threaten U.S. territory, Pikayev said.

However, a hawkish former top Russian military official, Col.-Gen. Leonid Ivashov, said that Washington had tried unsuccessfully to put the issue on the agenda of talks three times in the past, Interfax reported.

Ivashov spoke out strongly against any negotiations on tactical nuclear weapons, saying information about them "is perhaps the only military secret that we have," Interfax reported.