The joint drills come at a time when Trump is eyeing higher payments for the US troops stationed in South Korea. Meanwhile, Seoul ordered the partial, phased implementation of existing pacts made with North Korea.

South Korea and the United States began their annual large-scale joint military exercise on Monday to better cope with threats by nuclear-armed North Korea.

North Korea's Supreme Leader Kim Jong Un remained unhappy as the U.S. and South Korea conducted their annual summer joint military drills.