President Donald Trump ordered the US military on Friday to elevate its cyber warfare operations to a separate command, signaling a new strategic emphasis on electronic and online offensive and defensive operations.

"This new Unified Combatant Command will strengthen our cyberspace operations and create more opportunities to improve our nation's defense," Trump said in a statement.

"The elevation of United States Cyber Command demonstrates our increased resolve against cyberspace threats and will help reassure our allies and partners and deter our adversaries."

The move would expand the number of the Defense Department's unified combatant commands to 10, putting cyber warfare on an equal footing with the Strategic Command, the Special Operations Command, and regional commands.

Until now cyber warfare operations have been run under the umbrella of the National Security Agency, the country's main electronic spying agency, with Admiral Michael Rogers heading both.

Discussions on whether to hive it off and place it directly under Pentagon direction have gone on for several years. Rogers has said several times over the past year that they needed to recruit hundreds more skilled cyber operators before the separation could take place.

Trump's statement suggested the final shape of where the new unified command will fit into the Pentagon remains unsettled. Defense Secretary Jim Mattis is currently reviewing separating the Cyber Command from the NSA, he said.