MOSCOW (Reuters) - Russia’s Defence Ministry said on Saturday a U.S. plan to shoot down an ailing spy satellite could be used as a cover to test a new space weapon.

The ministry said there was insufficient proof that Washington’s decision to fire a missile at the disabled satellite was to prevent a potentially deadly leak of toxic gas as it re-entered Earth’s atmosphere.

“In our opinion, the decision to destroy the U.S. satellite is not as harmless as it is being presented. Especially as the United States has been avoiding talks on restricting a space arms race for quite a long time,” the ministry’s information department said in a statement.

“Under cover of discussions about the danger posed by the satellite, preparation is going ahead for tests of an anti-satellite weapon. Such tests mean in essence the creation of a new strategic weapon.”

U.S. officials said on Thursday that President George W. Bush had decided to have the Navy shoot the 5,000-pound (2,270 kg) satellite with a modified tactical missile after security advisers suggested its re-entry could lead to a loss of life.

Some space and security experts have said they did not believe Washington’s justification for the plans and argued the Pentagon was more likely testing its ability to target other states’ satellites.

This suggestion is rejected by U.S. officials.

It will be the first time the United States has conducted an anti-satellite operation since the 1980s. Russia also has not conducted anti-satellite activities in 20 years.