An annual joint military exercise between South Korea and the U.S. has ended after eleven days.

The exercise, which began Monday last week, involved some 20-thousand Korean and 18-thousand U.S. troops. The drill focused on reviewing Korea's defensive posture and U.S. reinforcement capacity for a contingency on the Korean Peninsula.

The two nations will evaluate this year’s military exercise on Friday and Monday.

North Korea, as usual, slammed this year’s Key Resolve as an exercise to prepare for an invasion of the North and kept its military on alert throughout the exercise.