Former president Thabo Mbeki reportedly held "private talks" with Zimbabwean President Robert Mugabe, 93, after he flew to Harare on Monday.

According to NewsDay, South Africa’s ambassador to Zimbabwe, Mphakama Mbete, said Mbeki’s visit was at Mugabe’s invitation.

"They were discussing experiences in South Africa and Zimbabwe, as well as the issue of liberation movements, as indicated by President Mugabe last month," Mbete was quoted as saying.

Mugabe's spokesperson George Charamba also confirmed Mbeki’s visit.

"Yes, they met, it was strictly at his (Mbeki's) request and strictly private. We didn’t even attend," Charamba was cited as saying.

Mbeki’s visit came at a time when the issue of succession was currently rocking the ruling Zanu-PF party, with Mugabe’s wife Grace making headlines last week after she called on the veteran leader to name his successor.

Mugabe has failed to groom a successor in his 37 years in power. He admitted at a recent rally in Chinhoyi that his party was sharply divided and called for unity among Zanu-PF members as Zimbabweans prepared for general elections due next year.