WASHINGTON (AFP) - President Donald Trump launched a new Pentagon command dedicated to warfare in space on Thursday (Aug 29), as American military chiefs see China and Russia pressing hard to erode the US advantage in the newest military frontier.

"This is a landmark day, one that recognizes the centrality of space to America's security and defence," Trump said in a White House ceremony.

"SpaceCom will ensure that America's dominance in space is never threatened."

The new command will elevate space - largely the satellites and high-altitude aircraft essential to modern-day warfare - to a focused theater of combat, the equivalent of US Central Command governing the Middle East and the Pacific Command, which manages US defenses in the Western Pacific and South-east Asia.

While the Department of Defence already has a unit of the Air Force focused on space warfare, the new command will heighten its importance and foster the specialised systems and training for Star Wars-type showdowns.

Air Force General John Raymond, who will lead the new command, said US rivals are already focused firmly on how to fight in space as part of a broader conflict.

"We are at a strategic inflection point where there is nothing that we do as a joint coalition force that isn't enabled by space," Raymond said.

"I'm convinced that space is a war-fighting domain. I'm convinced that our way of life and our way of war depend on space capabilities," he said.