Space ties with US 'strong and growing'

Australia's armed forces have pledged to work closely with the United States as it establishes a new branch of the military dedicated to fighting wars in space.

The Defence Department says decisions on the structure of the so-called Space Force are a matter for the US, as Donald Trump considers an extra agency on par with the army, navy, air force, marines and coast guard.

"Australian defence cooperation with the United States on space is strong and growing. This will continue irrespective of how the US military force is structured," a spokesperson told AAP on Monday.