United Nations Security Council Resolution 83
The United Nations Security Council Resolution 83, adopted on 27 June 1950, determined that the attack on the Republic of Korea by forces from North Korea constituted a breach of the peace. The United Nations Security Council (UNSC) called for an immediate cessation of hostilities and for the authorities in North Korea to withdraw their armed forces to the 38th parallel.
Source: Wikipedia — United Nations Security Council Resolution 83 (CC BY-SA 4.0)