Grace is very mature and can cope with criticism, says Mugabe

Grace Mugabe is "very mature" and can cope with the criticism she's come in for since she entered Zimbabwean politics less than two years ago, her husband says.

In an interview to mark his 92nd birthday that was screened on state ZBC television late on Thursday, President Robert Mugabe agreed that his 50-year-old wife had found herself in "rough waters".

"Yes, it has proved to be rough waters but... she can cope with it. She's a rough swimmer," Mugabe told interviewer Tazzen Mandizvidza.

The president's wife burst onto Zimbabwe's political scene in mid-2014, leading a vitriolic campaign to get then vice president Joice Mujuru unseated.

The formerly demure first lady is now head of the powerful ruling party's women's league - and lately appears to be at loggerheads with current vice president Emmerson Mnangagwa.

She denies that she has ambitions to succeed her husband, who has been in power in Zimbabwe since independence in 1980. Not everyone believes her.

Mugabe indicated that he was frustrated with what he called "rotten" internet reporting on his wife.

"It's an internet of dirt and filthy language," he said.