Zimbabwe's president has warned against messing with his family, amid a heated debate within the ruling party about his wife's entry into politics.

Robert Mugabe's 49-year-old wife Grace accepted a nomination last month to lead the ruling party's women's wing, triggering accusations that Mugabe aims to set a political dynasty in place.

Mugabe told hundreds of cheering youths at the airport that he heard that someone told his nephew to tell Grace to leave Harare. Mugabe said Wednesday: "We don't want such arrogance."

Mugabe, 90, will have to approve Grace's nomination during a congress in December.

Mugabe, who has ruled since 1980 and won re-election in a disputed poll last year, has already accepted a proposal by the women's wing to be the party's candidate for the 2018 election.