Russian Foreign Ministry says US strategy gives "green light to the prospect of basing missile strike capabilities in space," which is confrontational.
Russia said on Friday Washington's new missile defence strategy would lead to a dangerous arms race in space and amounts to a relaunch of the Cold War-era "Star Wars" programme.
In a statement, the Russian Foreign Ministry described the US plan as confrontational and said it would deal a blow to already-fragile international stability.
"We are especially alarmed by the passages dealing with plans to develop the space arm of US missile defence," the statement said. "The strategy de facto gives the green light to the prospect of basing missile strike capabilities in space."
US President Donald Trump on Thursday unveiled a plan that called for developing space-based sensors to detect incoming enemy missiles and exploring space-based weapons to shoot down missiles, among other steps to shield the United States.
"The implementation of these ideas will inevitably lead to the start of an arms race in space, which will have the most negative consequences for international security and stability," the Russian Foreign Ministry said.
"We would like to call on the US administration to think again and walk away from this irresponsible attempt to re-launch, on a new and more high-tech basis, the still-remembered Reagan-era 'Star Wars' programme," the statement said.
The ministry urged Washington to engage with Russia in constructive talks about the nuclear arms balance "before it's too late."
'An extremely dangerous situation'
Meanwhile, the head of the Nobel Prize-winning International Campaign to Abolish Nuclear Weapons (ICAN) said the world needs to "stop being passive" while the US and Russia decide whether to let a crucial nuclear arms control treaty collapse.
Beatrice Fihn, who leads ICAN, described the potential failure of the pact as "an extremely dangerous situation."
The United States and Russia agreed to the Intermediate-Range Nuclear Forces Treaty in 1987.
But last month Washington gave Russia a 60-day deadline – which ends on February 2 – to dismantle missiles that it claims breach the INF treaty or the US would begin the six-month process of formally withdrawing from the deal.
"If this treaty falls apart and the US withdraws ... then both these countries are free to put in place these intermediate missiles on the borders of Europe," Fihn said in an interview on Thursday.
Rest of world 'left on sidelines'
She told AFP that the rest of the world had been "left on the sidelines just watching [US President Donald Trump and Russian President Vladimir Putin] and their egos" decide the fate of the vitally important treaty.
Russia denies it has violated the treaty, which forbids ground-launched short- and intermediate-range missiles.
Russian Foreign Minister Sergey Lavrov has said Moscow is ready to work with Washington to save the agreement after bilateral talks in Geneva on the INF this week failed to resolve the impasse.