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.

South Korea’s birth rate has dropped throughout much of the past decade, spelling trouble for the military as regional threats and global conflicts simmer.

South Korea will end some military activities along its border with North Korea, President Lee Jae Myung said on Friday, in his government's latest effort to improve ties between the neighbouring countries still technically at war.