WASHINGTON, Dec. 18 (Xinhua) -- U.S. President Donald Trump issued an order Tuesday directing the establishment of "Space Command."

Trump said the new command will be created as a "unified combatant command," according to his memo to Defense Secretary Defense Jim Mattis, which was made public by the White House.

The Space Command will oversee all U.S. military activities in space, and the president has asked Mattis to recommend officers for the command's leadership, the memo said.

A comprehensive list of authorities and responsibilities for the Space Command will be included in the next update to the Unified Command Plan, it added.