The chief of space operations said a direct line of communication between the Space Force and its Chinese counterpart would be valuable in de-escalating tensions but that the U.S. had not yet engaged with China to establish one.

"What we have talked about on the U.S. side at least is opening up a line of communication to make sure that if there is a crisis, we know who we can contact," Saltzman said, adding that it would be up to President Joe Biden and the State Department to take the lead on such discussions.

The comments come as the U.S. Space Force looks into establishing a branch in Japan, as China's military ambitions in the Indo-Pacific unnverve its neighbours and the war in Ukraine spotlights the importance of space capabilities in warfare.

Japan has been especially concerned about Taiwan and any lessons China may have drawn from Russia's invasion of Ukraine a year ago. China, which views democratically governed Taiwan as its own territory, has not renounced the use of force to bring the island under Beijing's control.

Saltzman, who held talks with top Japanese defence officials in Tokyo on Monday, confirmed that the space force was exploring the potential establishment of a local headquarters in Japan.

He did not elaborate on the location or the purpose it would serve, but did say it could look similar to a branch established in South Korea in November last year.

Saltzman added that deeper cooperation with like-minded countries including Japan would be crucial in being able to monitor and understand activity in the space domain to deter China and counter 'grey zone activities' such as jamming satellite signals.

"We have to be able to have those indications and warnings and see what they're doing and call them on the intent. Just being hypersensitive so we don't fall prey to grey zone activities," Saltzman said.

The U.S. Space Force, founded in 2019, also does not have a direct line of communication with its Russian counterpart.