Talks stagnated during the following decade as the civil war in Angola continued. It was not until 1988 that Cuba, Angola, and South Africa came to an agreement, called the "Tripartite Accord" or the "New York Accords," mediated by US Assistant Secretary of State Chester Crocker. A series of meetings starting in London and culminating in Geneva resulted in a ceasefire agreement, set to begin on 8 August 1988. A final meeting in Brazzaville, Congo set 1 April 1989 as "D-Day" when the implementation of United Nations Security Council Resolution 435 would begin. The New York Accords between Cuba, Angola and South Africa were formally signed at UN headquarters in New York City on 22 December 1988, officially ending the South African Border War though the ceasefire collapsed in Angola several months later.