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.

Ulchi Freedom Shield will involve 21,000 soldiers in computer-simulated command post operations and field training.

The powerful sister of North Korea's leader on Thursday denied reports by the South Korean military that Pyongyang has started removing loudspeakers used in tit-for-tat propaganda wars along their border.