"Permanent representative of North Korea to the United Nations [Ja Song Nam] sent a letter to the UN secretary-general on March 22 due to a tense situation on the Korean peninsula caused by the largest in the history joint military drills of the United States and South Korea," the statement said.
The letter provided details on the scale, aim and danger of joint US-South Korean military exercises, according to the diplomatic mission.
On March 1, the United States and South Korea launched the Foal Eagle military exercises involving air, naval and ground forces, which are scheduled to run through April. According to Robert Wood, the US permanent representative to the Conference on Disarmament, the drills were aimed at keeping stability on the Korean peninsula, however, a Chinese representative warned that the maneuvers would lead to further escalation of the situation with North Korea.
Tensions on the Korean Peninsula escalated since North Korea carried out a number of missile launches and nuclear tests, with one of the latest being a launch of four missiles in the direction of the Sea of Japan conducted on March 6 and a new high-thrust rocket engine tested on the ground on Sunday. The launches are considered to be in violation with the UNSC resolution by the United Nations.