The command will be separate from Trump's goal to build an entirely new branch of the military called "Space Force," which has not received approval from Congress.

"I direct the establishment, consistent with United States law, of United States Space Command as a functional Unified Combatant Command," Trump said in a memo to Defense Secretary Defense Jim Mattis.

Speaking at the Kennedy Space Center in Florida's Cape Canaveral, Vice President Mike Pence said Space Command would integrate space capabilities across all branches of the military.

"It will develop the space doctrine, tactics, techniques and procedures that will enable our war fighters to defend our nation in this new era," Pence said.

SpaceCom, as it will inevitably come to be known, will be the Pentagon's 11th combatant command.

America's vast military divides the globe into various commands, such as Central Command in the Middle East or Indo-Pacific Command in Asia. The new Space Command would be on equal footing with these.

It will require a new headquarters, as well as a commander and deputy commander who will need Senate approval.

Trump in June said he wanted to create a "Space Force," which would be a sixth and entirely new branch of the military alongside the Navy, Marine Corps, Army, Air Force and Coast Guard.

He insists such a move is necessary to tackle vulnerabilities in space and assert US dominance in orbit.

But its creation is not a done deal, as it needs to be approved by Congress, and the concept has met with some skepticism from lawmakers and defense officials wary of the cost and added bureaucracy.

The creation of a new Space Force would also set off a turf war within the Pentagon, particularly with the Air Force, which currently is responsible for most space operations.

- New satellites -

Pence spoke to an audience in Florida, where he had been expecting to watch the launch of a SpaceX rocket carrying a new generation of satellite, ordered by the US Air Force, that are much harder for adversaries to jam.

Additional "GPS III," or third generation, satellites will be launched in the coming years, creating a new constellation of the orbiting craft.

The Air Force asked for $1.5 billion for fiscal year 2019 for the program.

Space plays a vital role in just about every aspect of modern warfare, with many military technologies reliant on a network of orbiting sensors and satellites, and the Pentagon has warned that countries like Russia and China are working to build anti-satellite capabilities.

Tuesday's launch was scrubbed at the last minute due to an issue with some sensor readings, SpaceX said. It has been rescheduled for Wednesday morning.

In a series of tweets, Deputy Defense Secretary Patrick Shanahan said the creation of Space Command is a "critical step" in America's ability to manage space as a warfighting domain.

"US Space Command will allow us to accelerate our space capabilities to defend our National interests and deter our adversaries," he said.

Shanahan added that the Pentagon is working on a legislative proposal that would meet Trump's vision for a separate Space Force.