United Nations Command The United Nations Command ( UNC ) is the unified command structure for the multinational military forces supporting the Republic of Korea ( South Korea or ROK ) during and after the Korean War . After troops of the Democratic People ' s Republic of Korea ( North Korea or DPRK ) invaded South Korea on June 25 , 1950 , the United Nations Security Council adopted Resolution 82 calling on North Korea to cease hostilities and withdraw to the 38th parallel . On June 27 , 1950 , it adopted Resolution 83 , recommending that members of the United Nations provide assistance to the Republic of Korea " to repel the armed attack and to restore international peace and security to the area " . Security Council Resolution 84 , adopted on July 7 , 1950 , recommended that members providing military forces and other assistance to South Korea " make such forces and other assistance available to a unified command under the United States of America " . On August 29 , 1950 , the British Commonwealth ' s 27th Infantry Brigade arrived at Busan to join the UNC , which until then included only ROK and U . S . forces . The 27th Brigade moved into the Naktong River line west of Daegu . Troop units from other countries of the UN followed in rapid succession ; Australia , Belgian United Nations Command , Canada , Colombia , Ethiopia , France , Greece , Luxembourg , the Netherlands , New Zealand , the Philippines , Thailand and Turkey . The Union of South Africa provided air units which fought alongside the air forces of other member nations . Denmark , India , Norway , and Sweden provided medical units . Italy provided a hospital , even though it was not a UN member . The United Nations Command and the Chinese - North Korean Command signed the Korean Armistice Agreement on 27 July 1953 , ending the heavy fighting . The armistice agreement established the Military Armistice Commission ( MAC ) , consisting of representatives of the two signatories , to supervise the implementation of the armistice terms , and the Neutral Nations Supervisory Commission ( NNSC ) to monitor the armistice ' s restrictions on the parties reinforcing or rearming themselves . The North Korean - Chinese MAC has been replaced by Panmumjon Representatives under exclusive North Korean management . Regular meetings have been stopped , although duty officers of Joint Security Area , commonly known as the Truce Village of Panmunjom , from each side meet regularly . Legal status . Although the resolutions suggested the forces under the UNC were " United Nations forces " , and United Nations itself could be considered a belligerent in the war , in practice the United Nations exercised no control over the combat forces , which were controlled by the United States . Most observers concluded that the forces under the UNC were not in law United Nations troops , and the acts of the UNC were not the acts of the United Nations . The UNC can be regarded as an alliance of national armies , operating under the collective right of self - defense . United Nations Security Council Resolution 84 authorized the use of the United Nations flag concurrently with the flags of the participating UNC nations . In 1994 , the UN Secretary General in a letter to the North Korean Foreign Minister distanced the UN from the UNC by writing " the Security Council did not establish the unified command as a subsidiary organ under its control , but merely recommended the creation of such a command , specifying that it be under the authority of the United States . Therefore the dissolution of the unified command does not fall within the responsibility of any United Nations organ but is a matter within the competence of the Government of the United States . " 1950 – 1953 . During the three years of the Korean War , military forces of these nations were allied as members of the UNC . Peak strength for the UNC was 932 , 964 on July 27 , 1953 , the day the Armistice Agreement was signed : The commanders of the UNC were : Douglas MacArthur , Matthew B . Ridgway , James Van Fleet , and Mark Wayne Clark 1953 onwards . In the confusion of the early days of the Korean War , Seoul placed its armed forces under the command of General Douglas MacArthur as United Nations ( UN ) commander . This arrangement continued after the armistice . For some twenty - five years , the United Nations Command headquarters , which had no South Korean officers in it , was responsible for the defense of South Korea , with operational control over a majority of the units in the Republic of Korea Armed Forces , the South Korean military . The command was the primary peacetime planning organization for allied response to a North Korean invasion of South Korea and the principal wartime command organization for all South Korean and United States forces involved in defending South Korea . In 1978 a binational headquarters , the Republic of Korea – United States Combined Forces Command ( CFC ) , was created , and the South Korean military units with front - line missions were transferred from the UN Command to the CFC ' s operational control . The commander in chief of the CFC , a United States military officer , answered ultimately to the national command authorities of the United States and the Republic of Korea . Under the law , the Commander , United States Forces Korea , is dual - hatted as Commander of the ROK - US CFC . The Deputy Commander is a 4 - star general from the ROK Army , who is also dual - hatted as the ground forces component commander .