United Nations: North Korea and South Korea asked the United Nations on Friday to circulate a peace declaration their leaders agreed to in April, that vows to remove nuclear weapons from the Korean peninsula and work toward a formal end to the Korean War.

North Korea's UN Mission said ambassadors of the two countries sent a letter to Secretary-General Antonio Guterres and General Assembly President Miroslav Lajcak requesting that they circulate the "Panmunjom Declaration on Peace, Prosperity and Reunification of the Korean Peninsula" as an official UN document.

UN deputy spokesman Farhan Haq said the letter had been received and was being processed.

North Korean leader Kim Jong Un and South Korean President Moon Jae-in agreed to the declaration at a summit in the demilitarized zone in Panmunjom on April 27 where the two men from nations with a deep and bitter history of acrimony held each other's hands and walked over each side of the border.

North Korea said the request to circulate the document to the 193 UN member states "shows the full determination of North and South Korea to keep advancing the North-South ties without deviation" and to demonstrate that they "have entered definitely the new orbit of peace, the orbit of reconciliation and cooperation."

North Korea said active support from all UN members to implement the declaration "would exert great encouragement to the dramatic changes towards relaxation of the tension and the peace on (the) Korean peninsula."

The joint letter follows the recent resumption of temporary reunions of relatives from the two Koreas separated by the 1950-53 Korean War and comes days after top South Korean security officials returned from a meeting with Kim in Pyongyang. They announced that Kim and Moon would hold their third summit on September 18-20 in Pyongyang, just before world leaders gather for their annual meeting at the UN General Assembly.

Chung Eui-Yong, Moon's national security adviser and the head of the South Korean delegation, said Kim told him that he still had faith in President Donald Trump despite diplomatic setbacks and wishes for North Korea and the US to put an end to their seven decades of hostile relations before the end of Trump's first term.

Kim told Chung that work to dismantle the only missile engine test site in North Korea "means a complete suspension of future long-range ballistic missile tests." The North Korean leader also said he would take "more active" measures toward denuclearization if his moves are met with corresponding goodwill measures, Chung said.

While the April declaration's language on denuclearization was considered weak, the document made inroads on a raft of other points of friction between the two Koreas. They agreed to settle their disagreement over their western maritime border by designating it as a peace area and securing fishing activities for both countries.

Both leaders said they would meet on a regular basis and exchange calls via a recently established hotline and would open a permanent communication office in the North Korean border town of Kaesong.

Both Koreas also said they would jointly push for talks with the United State and also potentially China to officially end the Korean War, which stopped with an armistice that did not formally end the war.