The U.S. military is preparing for the possibility that future conflicts could extend beyond Earth’s orbit and into the region surrounding the Moon, Gen. Dan Caine said Wednesday at the Air, Space & Cyber Conference in Maryland. Caine said the military must be prepared to “fight, endure and win” across the battlefield from the seabed to cislunar space.

Cislunar space refers to the area between Earth and the Moon. Lt. Gen. Gregory Gagnon, head of Space Force Combat Forces Command, said the service is preparing for operations in that region as human activity expands deeper into space and potential adversaries develop their own capabilities.

The comments came shortly after Air Force Secretary Troy Meink revealed that the United States has deployed “on-orbit space control weapons” capable of defending U.S. forces against hostile action. The military has not disclosed what the weapons are, how many are deployed, or their specific capabilities.

U.S. officials have pointed to China and other potential adversaries as reasons for expanding American space capabilities. China established its own military space force in 2024, while Beijing has criticized the U.S. deployment and called for an end to the expansion of military capabilities in space.

The developments have also raised questions about international agreements governing military activity beyond Earth. The 1967 Outer Space Treaty prohibits placing nuclear weapons and other weapons of mass destruction in orbit, while establishing requirements concerning the use of celestial bodies and responsibility for space objects. U.S. officials maintain that the Space Force will conduct safe and responsible operations.

The Space Force is also planning significant growth. Gagnon said the service aims to roughly double its personnel over the next five years to about 25,000 members, with approximately two-thirds of the increase focused on its combat forces. Officials say the expansion is intended to strengthen deterrence as military competition increasingly extends into space.