Building a more lethal force is the Pentagon’s top priority, Defense Secretary Jim Mattis said. “We have no room for complacency in any domain,” he said.

His remarks came as the Defense Department has elevated the U.S. Cyber Command to the status of a full combatant command and is taking the first steps toward creating the U.S. Space Force as a new and separate armed service. Outer space and cyberspace are “warfighting domains on par with air, land and sea,” he said.

Paying for those developments will require juggling, potentially cutting other programs. DoD reforms resulted in almost $4 billion in savings in fiscal 2018, which ends Sept. 30, Mattis said, which will help with the costs.

Congress is still working on the fiscal 2019 budget. The House and Senate each have passed their own versions, with negotiations underway on a compromise measure.