The Russian space agency, Roscosmos, has accused Donald Trump of creating a basis to take over other planets by signing an executive order outlining US policy on commercial mining in space.
The executive order, which Roscosmos said damaged the scope for international cooperation in space, was signed on Monday.
The new order largely clarifies the existing US position – that companies should be able to profit of space resources. In 2015 congress signed a bill to allow Americans to use resources on the moon and passing asteroids.
The new presidential order goes one step further to state that US citizens should have the right to engage in such activity and that "outer space is a legally and physically unique domain of human activity, and the United States does not view it as a global commons".
It said the United States would seek to negotiate "joint statements and bilateral and multilateral arrangements with foreign states regarding safe and sustainable operations for the public and private recovery and use of space resources".
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Roscosmos said the order put the United States at odds with the notion of space belonging to all humanity.
"Attempts to expropriate outer space and aggressive plans to actually seize territories of other planets hardly set the countries [on course for] fruitful cooperation," its statement said.
Relations between Russia and the United States are at post-Cold War lows, but cooperation on space has continued despite an array of differences over everything from Ukraine to accusations of election meddling.
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Kremlin spokesman Dmitry Peskov told reporters that "any kind of attempt to privatise space in one form or another - and I find it difficult to say now whether this can be seen as an attempt to privatise space - would be unacceptable".
NASA, the US space agency, is aiming to return humans to the Moon and wants to build a permanent base on Earth's nearest neighbour before the end of the decade. The new order simply clarifies Washington's position on materials in space, officials said.
"As America prepares to return humans to the moon and journey on to Mars, this executive order establishes US policy toward the recovery and use of space resources, such as water and certain minerals, in order to encourage the commercial development of space," said Scott Pace, deputy assistant to the president and executive secretary of the US National Space Council.
Mr Trump has repeatedly promised to send astronauts to the moon, something no nation has done since 1972.
Initially, Nasa had planned to return to the Moon by 2028.
Last year, Vice President Mike Pence said, "That's just not good enough. We're better than that. It took us eight years to get to the moon, the first time, 50 years ago, when we had never done it before".