Zimbabwe's ex-leader Robert Mugabe is in Singapore for medical care and now unable to walk because of ill health and old age, President Emmerson Mnangagwa said on Saturday.

Mnangagwa told his ZANU-PF party supporters at a rally that the 94-year-old Mugabe had been receiving medical care in Singapore for the past two months.

"He (Mugabe) is now old. Of course, he now is unable to walk but whatever he asks for we will provide," Mnangagwa told hundreds of supporters in Mugabe's home area of Zvimba, about 100 km (60 miles) west of the capital Harare.

"We are looking after him. He is the founding father of the nation of Zimbabwe. He is our founding father of free Zimbabwe."