Countering China's rapidly expanding military and an increasingly aggressive Russia are now the U.S. military's top national security priorities. Defense Secretary Jim Mattis says they even outpacing the threat of terrorism. He said Friday that competition with those adversaries has threatened America's military advantage around the world.

Mattis is laying out a broad new strategy for the Defense Department. And he warns that all aspects of the military's competitive warfighting edge have eroded.

He said building a force that can deter war with established and emerging military powers in Moscow and Beijing, and U.S. enemies such as North Korea and Iran will require increased investment to make the military more lethal, agile and ready to fight.