The US Space Force has confirmed for the first time that Washington has weapons deployed in orbit, as the United States, China and Russia expand their military capabilities in space.
The disclosure highlights a growing focus on controlling the space domain and protecting satellites vital to military communications, surveillance and navigation.
A US Space Force spokesperson said: "Space control encapsulates the mission areas required to contest and control the space domain – employing kinetic and non-kinetic means to affect adversary capabilities through disruption, degradation and even destruction, if necessary. These capabilities can be employed for offensive and defensive purposes at the direction of combatant commands."
Details of how the weapons operate have not been disclosed by US officials.
China responded by warning against an "arms race" in space. "We urge the US side to stop expanding its military capabilities and preparing for war in outer space," a Chinese foreign ministry spokesman said.
An expert on military uses of outer space noted that "precious little" was publicly known about the technology, saying there could be a "whole range of different weapons systems."
Dr Bleddyn Bowen, from the Royal United Services Institute, said he was "totally guessing" but that the US could have been referring to "some kind of electronic warfare or radio jamming platform." That would be the sort of weapon that already exists on Earth and could disrupt radio communications.
An alternative, Bowen said, would be "a kinetic kill vehicle of some sort - so a vehicle that would release a projectile of some sort that would ram into a satellite and destroy it." He added this was less likely, however, because such a physically destructive tool would be capable of creating a large amount of debris.
The Trump administration has said that space-based capabilities and interceptor missiles are a crucial part of its planned "Golden Dome" defence system, designed to protect the United States from missiles and other airborne threats.
Last year, President Donald Trump issued an executive order underlining the US Space Force's role not only in defending assets, but also as an attacking force.
The US Space Force, the first new branch of the US military in more than 70 years, was established in 2019 to protect American assets in space, including hundreds of satellites used for communication and surveillance.
A 1967 treaty banned weapons of mass destruction in orbit. Since then, key powers including the United States, Russia and China have been exploring capabilities outside the treaty, such as targeting rivals' satellites, which are critical for military communications, surveillance and navigation.
The US Space Force has stated that China "develops and operates space and counterspace capabilities as part of a military modernisation strategy," while Russia "views space as a warfighting domain and believes space supremacy will be a decisive factor in future conflicts."
In early February, it was revealed that two Russian satellites had likely intercepted the communications of at least a dozen European satellites since Russia's invasion of Ukraine in 2022. Such interceptions may have allowed Russian intelligence services to read sensitive transmitted data or, hypothetically, to take control of the satellites.
In 2024, the United States said Russia had launched a satellite it believed may be capable of attacking other spacecraft. Russia did not publicly comment on the matter.
