President Robert Mugabe has called on neighbouring countries not to interfere in Zimbabwe's internal affairs, while signalling that constitutional reform was on the cards, possibly to smooth the way for a chosen successor. Speaking in a televised interview to commemorate his 82nd birthday over the weekend, Mugabe said: "We have tolerated some of them because they are our friends. We hope in future they will keep away." He was responding to a question on what he thought of diplomatic interventions by South Africa and Nigeria in Zimbabwe's political crisis. Mugabe sneered at his colleagues in the African Union, suggesting their interest in resolving Zimbabwe's problems was more to do with pressure from western governments deemed hostile to his ruling ZANU-PF.