On February 23, 1970, Guyana declared itself a "cooperative republic" and cut all ties to the British monarchy. The governor general was replaced as head of state by a ceremonial president. Relations with Cuba were improved, and Guyana became a force in the Nonaligned Movement. In August 1972, Burnham hosted the Conference of Foreign Ministers of Nonaligned Countries in Georgetown. He used this opportunity to address the evils of imperialism and the need to support African liberation movements in southern Africa. Burnham also let Cuban troops use Guyana as a transit point on their way to the war in Angola in the mid-1970s.