Trump ordered an "Iron Dome for America" shortly after his inauguration in January, a programme to counter ballistic and hypersonic missile threats.
The plan revives parts of a controversial Reagan-era plan nicknamed "Star Wars" that would have placed missile interceptors in space.
"The recently announced large-scale 'Golden (Iron) Dome for America' programme is also deeply destabilising," Russia and China said in a statement published by the Kremlin after talks between presidents Vladimir Putin and Xi Jinping in Moscow.
The plan "explicitly provides for a significant strengthening of the arsenal for conducting combat operations in space", it added.
The two countries said they would start talks on preventing the deployment of arms in space and would "counter policies and activities aimed at achieving military supremacy and formalising the use of space as a battlefield".
Trump's proposal, which the US president has also called the "Golden Dome", refers to a highly successful system employed by Israel to down short-range rockets.
Washington faces various missile threats from adversaries, but they differ significantly from the short-range weapons that Israel's Iron Dome is designed to counter.
Russia, which commands the world's largest nuclear arsenal, last year unveiled a new hypersonic missile known as "Oreshnik", a weapon experts believe flies at 10 times the speed of sound.
Beijing has been closing the gap with Washington when it comes to ballistic and hypersonic missile technology, according to the US National Defence Strategy released in 2022.
Russia and the US have traded accusations of weaponising space in recent years.
Related Links
Learn about missile defense at SpaceWar.com
Learn about nuclear weapons doctrine and defense at SpaceWar.com
All about missiles at SpaceWar.com
Learn about the Superpowers of the 21st Century at SpaceWar.com
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
