Today Nexon announced a new co-op mode set to be added to Combat Arms next week. The mode will be known as "Fireteam Mode", and the official US Combat Arms website describes it as such:

"Fireteam Mode brings cooperative gameplay to Combat Arms. Play with up to eight players in an intense multi-staged hostage rescue mission. Team up with your fellow soldiers to defeat the enemy army!"

This sounds familiar to the campaign mode already released in Combat Arms Korea, which we know very little about as of yet. Fireteam Mode will be added as part of a patch on May 27th. You can check out the trailer for the new mode here.