Mbeki mediated in issues on the African continent including: Burundi, the Democratic Republic of Congo (DRC), Ivory Coast, and some important peace agreements. Mbeki oversaw the transition from the Organisation of African Unity (OAU) to the African Union (AU). His "quiet diplomacy" in Zimbabwe, however, is blamed for protracting the survival of Robert Mugabe's regime at the cost of thousands of lives and intense economic pressure on Zimbabwe's neighbours. He became a vocal leader of the Non-Aligned Movement in the United Nations, and, while leveraging South Africa's seat on the Security Council, he agitated for reform of that body.