The Chinese government says US President Donald Trump’s plan for a “Golden Dome” missile defence shield risks weaponising space, and is urging him to scrap the project.

Trump and US Defence Secretary Pete Hegseth this week unveiled the plan for a $US175 billion ($276 billion) anti-missile umbrella to protect the US against attacks.

The pair announced the news in the Oval Office of the White House beside a poster showing the continental US painted gold and with artistic depictions of missile interceptions.

Trump said the defence system would be capable of of intercepting missiles “even if they are launched from space”.

But spokesperson for the Chinese Foreign Ministry Mao Ning told a media briefing yesterday the plan risked triggering an arms race in space and would violate established treaties.

“It plans to expand the US arsenal of means for combat operations in outer space, including R&D and deployment of orbital interception systems. That gives the project a strong offensive nature and violates the principle of peaceful use in the Outer Space Treaty.

“The project will heighten the risk of turning the space into a war zone and creating a space arms race, and shake the international security and arms control system.”

She said China was “gravely concerned” by the US plan and urged Trump to abandon it.

The Pentagon has warned for years that the newest missiles developed by China and Russia are so advanced that updated countermeasures are necessary.

“Golden Dome’s” added satellites and interceptors, where the bulk of the program’s cost is, would be focused on stopping those advanced missiles early on or in the middle of their flight.

China and Russia have put offensive weapons in space, such as satellites with the ability to disable critical American satellites, which can make the US vulnerable to attack.

Last year, the US said Russia was developing a space-based nuclear weapon that could loiter in space for long durations, then release a burst that would take out satellites around it.

Trump said on Tuesday that he had not yet spoken to Russian President Vladimir Putin about the “Golden Dome” program, “but at the right time, we will”.

– With Associated Press