Rising space power China on Monday attacked the newly created US Space Force as a "direct threat to outer space peace and security".
Foreign ministry spokesman Geng Shuang told reporters that China is "deeply concerned about it and resolutely opposed to it".
"The relevant US actions are a serious violation of the international consensus on the peaceful use of outer space, undermine global strategic balance and stability, and pose a direct threat to outer space peace and security," Geng said at a regular briefing.
China's space program has advanced rapidly since its first crewed mission in 2003.
In a report last February, the Pentagon asserted that China and Russia have embarked on major efforts to develop technologies that could allow them to disrupt or destroy American and allied satellites in a crisis or conflict.
China in 2007 conducted an unannounced missile strike against one of its own defunct satellites, creating an enormous amount of space debris.
Geng dismissed such concerns, calling them "unfounded counter charges" that merely provided the US with a justification for its own actions. China, he said, has consistently opposed the weaponisation of space and believes international treaties on arms control in outer space need to be negotiated.
"We hope that the international community, especially the major powers concerned, will adopt a cautious and responsible attitude to prevent outer space from becoming a new battlefield and work together to maintain lasting peace and tranquility in outer space," he said.
The establishment of the Space Force is seen by the US military as a recognition of the need to more effectively organize for the defense of US interests in space especially satellites used for navigation and communication. The Space Force is not designed or intended to put combat troops in space.
Space has "evolved into a war-fighting domain of its own," Defence Secretary Mark Esper told reporters Friday.
Space has become increasingly important to the US economy and to everyday life.
The Global Positioning System, for example, provides navigation services to the military as well as civilians. Its constellation of about two dozen orbiting satellites is operated by the 50th Space Wing from an operations centre at Schriever Air Force Base in Colorado.
China has established a similar, independent network, the BeiDou Navigation Satellite System, assembled from 42 separate satellite launches.