Trump told troops at the Miramar Marine Corps Air Station near San Diego that the new group would be able to encapsulate the "tremendous amount" of work the military and government are doing in space-related defense.
"My new national strategy for space recognizes that space is a war-fighting domain, just like the land, air and sea," Trump said.
"We may even have a space force... We have the air force, we'll have the space force, we'll have the army, the navy.
"Maybe we'll have to do that. That could happen," he said.
Since taking office, Trump has frequently touted his support for the US military and placed high-ranking generals in top White House and cabinet posts.