The chief of Russia's space forces on Thursday said Moscow would have to retaliate if others deploy weapons in space — a stern warning to the United States.

While Col.-Gen. Vladimir Popovkin did not name any specific country, he was clearly referring to U.S. plans for space-based weapons, which the Kremlin had vociferously opposed.

"We don't want to wage a war in space, we don't want to gain dominance in space, but we won't allow any other nation to dominate space," Popovkin said in televised remarks. "If any country deploys weapons in space, then the laws of warfare are such that retaliatory weapons are certain to appear."

President Vladimir Putin has criticized U.S. plans for space-based weapons, saying it could trigger a new arms race.

When China tested an anti-satellite missile in January, Putin said that the move was a response to U.S. plans for space-based weapons.

Russia and China have strongly pushed for an international agreement banning space weapons, but their proposals have been stymied by the United States.

"It's necessary to legalize the game rules in space," Popovkin said. He warned that the complexity of space weapons could trigger a war.

Satellites may fail on technical reasons, but their owner could think they were incapacitated by an enemy and could be tempted to retaliate, Popovkin said.

"If that happens, a nation might ask a legitimate question: could it be the beginning of an effort to deafen and blind it," Popovkin said.

President Bush signed an order last year tacitly asserting the U.S. right to space weapons and opposing the development of treaties or other measures restricting them.

Bush also had pushed an ambitious program for space-based missile defense, and the Pentagon is working on missiles, ground lasers and other technology to shoot down satellites.

The U.S. plans have worried Russia, which also has strongly criticized U.S. plans to deploy missile defense elements in Poland and the Czech Republic. Putin has rejected U.S. assertions that the missile defense sites in Europe were necessary to confront a prospective missile threat from Iran and said they threatened Russia's nuclear deterrent.

The dispute has badly damaged the Russian-U.S. relations, also strained over U.S. criticism of the Kremlin's backsliding on democracy and rifts over global crises.

Popovkin said Russia would modernize components of its air and missile defense systems. He said, in particular, that the military would build a new early warning radar near Armavir in southern Russia's Krasnodar region to replace aging Soviet-built radars it currently shares with Ukraine.

Such radars are intended to detect the launch of an enemy's ballistic missiles.

Popovkin also said that Russia in 2009 would start testing a new generation of satellites to spot missile launches. He said more than 60 military and dual-purpose satellites are currently in orbit.