As the KRA made preparations for its war against Vietnam, state-controlled media in Vietnam sent congratulatory messages to the Government of the Democratic Kampuchea on the second anniversary of its establishment, on 17 April 1977. On 30 April 1977, the second anniversary of the fall of Saigon, the Kampuchean reply came in the form of a military attack against the Vietnamese provinces of An Giang and Châu Đốc, killing hundreds of Vietnamese civilians. The PAVN responded by moving its troops to areas attacked by Kampuchea and, on 7 June 1977, Vietnam proposed high-level talks to discuss outstanding issues. On 18 June 1977, the Kampuchean Government replied by demanding that Vietnam remove all of its military units from the disputed areas, and create a demilitarised zone between the opposing forces.