The United States and North Korea remain technically in a state of war due to the 1950-1953 Korean War having ended in a cease-fire, not a peace treaty.

The war began on June 25, 1950, with a North Korean invasion into South Korea. The U.S.-led United Nations forces fought alongside South Korea against the North, which was supported by China and the Soviet Union.

Hostilities ceased with an armistice agreement signed on July 27, 1953, by the U.S.-led U.N. Command, North Korea and China. South Korea refused to sign, however.

The Korean Peninsula has since been split in two along the Demilitarized Zone, a 4-kilometer-wide strip of land that runs for 250 km across peninsula, and has come to be known as the world's last Cold War frontier.

North Korea has long called for a peace treaty to formally end the war, but the United States has rejected it, saying it makes no sense to discuss the issue without making progress in Pyongyang's nuclear issue.

At the inter-Korean summit on April 27, North Korean leader Kim Jong Un and South Korean President Moon Jae In agreed to pursue "complete" denuclearization of the peninsula and to strive to declare a formal end to the Korean War this year.

U.S. President Donald Trump said earlier this month ahead of his first-ever summit with Kim on Tuesday in Singapore that Washington and Pyongyang could sign an agreement to end the Korean War.