President Robert Mugabe of Zimbabwe has sharply criticized the vice president, underscoring that she is no longer a favorite to succeed the 90-year-old leader.

Mugabe told military leaders and representatives of Zimbabwe's independence war veterans on Tuesday that Vice President Joice Mujuru was working with the political opposition as well as the United States, which has criticized Mugabe's human rights record. Mugabe's address was broadcast on state television.

This week, Zimbabwe's ruling party is holding a key congress at which Mugabe is poised to appoint a new set of loyalists, including his wife Grace.