US troops must be ready for space combat around moon, Trump’s top military adviser says

American troops must ready themselves for combat not only in Earth's orbit but in the region surrounding the moon, according to President Donald Trump’s top military adviser on Wednesday, following the first public revelation that the U.S. has deployed weapons in space.

Addressing military personnel and defense industry leaders at the Air, Space and Cyber Conference near Washington, chairman of the Joint Chiefs of Staff Gen. Dan Caine urged the armed services to adapt so the military "is prepared to fight, endure and win ... from the seabed to cislunar space."

The Space Force, the newest branch of the military established by Trump in 2019, is organizing to engage in combat within orbit and lunar space. Lt. Gen. Gregory Gagnon, head of the force’s Combat Forces Command, separately informed reporters that as "humanity is advancing deeper into space — the Space Force’s job is to help be prepared to defend U.S. interests.”

The disclosure that American forces are prepared to fight between high Earth orbit and the moon comes shortly after Air Force Secretary Troy Meink announced at the same event that the US has operational "on-orbit space control weapons."

The series of military statements regarding orbital armaments runs counter to long-established international norms intended to preserve outer space exclusively for non-militarized, peaceful purposes.

While several nations, including the US, have previously demonstrated the ability to destroy satellites in Earth orbit, those tests were conducted from terrestrial locations against their own assets.

According to Gagnon, however, "the intelligence community has been clear that potential adversaries have been seeking to extend warfare into space," compelling a reaction from the US military.

"Our potential adversaries such as the PRC are actively pursuing activities in the system, in parts of space," Gagnon said, referring to the People's Republic of China.

China created its own dedicated military space unit in 2024, assigning it to enhance its capability to handle conflicts in space.

Responding to the US announcements concerning space weapons, Chinese foreign ministry spokesperson Guo Jiakun told journalists on Tuesday that "China always upholds the peaceful use of outer space, maintains outer space security and opposes the weaponization, militarization and an arms race in outer space."

Guo also called on the U.S. to "stop expanding its military preparations in outer space."

It remains unclear whether placing weapons in orbit or planning for their potential employment around the moon breaches international treaties meant to limit space militarization.

The 1967 Outer Space Treaty, ratified by both the US and China, mandates that celestial bodies, including the moon, be used "exclusively for peaceful purposes," prohibits nuclear weapons in orbit, and dictates that nations remain "liable for damage caused by their space objects."

A renewed effort to strengthen UN anti-militarization rules occurred two years ago following US intelligence indicating Russia was constructing a space-based weapon.

Russia vetoed a joint US-Japanese resolution at the UN that called on all nations to refrain from deploying nuclear arms or weapons of mass destruction in space. A counter-resolution submitted by Russia to ban all weapons in space "for all time" also failed to pass.

When asked about treaty commitments, Gagnon asserted that the U.S. Space Force "will continue to execute safe and responsible space operations in all the reaches of space."

He declined to detail specific military policies regarding conventional armaments such as projectiles or bullets in space, directing questions to the Pentagon, which did not immediately comment.

Gagnon added that the US intends to double the size of the Space Force over the next five years to approximately 25,000 service members, with around two-thirds directed to Combat Forces Command.

"We have capabilities in the military because we are preparing to defend the nation," Gagnon said. "The reason we have the capabilities is to help create deterrence."