Zimbabwe will hold elections in four to five months, a newspaper on Thursday quoted President Emmerson Mnangagwa as saying, the first time since independence the southern African state will conduct a vote that does not involve Robert Mugabe.

The vote, a litmus test of Mnangagwa's democratic credentials, will be crucial to unlocking badly needed financial assistance and repairing relations with Western powers and international financial institutions.

Mnangagwa, a protege of Mugabe, came to power in November after a de-facto military coup when the 93-year-old was forced to resign after the military confined him to his Harare mansion.

It was the culmination of a power struggle between Mnangagwa and former first lady Grace Mugabe, who was being groomed by her husband as his potential successor.

Now Mnangagwa, 75, is under pressure himself to deliver on the economy and show that he is breaking with the policies of Mugabe, whose 37-year rule since independence in 1980 turned a promising country into a basket case and international pariah.

He promised the elections for the presidency, parliament and local government would be peaceful and told business leaders their investments would be secure and their profits safe.

"Zimbabwe is going for elections in four to five months' time and we have to preach peace, peace and peace because we know it is good for us and we have no doubt that we will have peaceful elections," Mnangagwa was quoted as saying by the official Herald newspaper during an official trip to Mozambique.

"We will ensure that Zimbabwe delivers free, credible, fair and indisputable elections to ensure Zimbabwe engages the world as a qualified democratic state."

Under the constitution, Zimbabwe should hold elections between July 22 and August 22, but parliament can choose to dissolve itself, triggering an earlier vote. The ruling Zanu-PF holds a two-thirds majority in parliament.

Since 2000, elections in Zimbabwe have been marred by political violence and disputes.

But the 2018 vote could catch the opposition flat-footed.

Mnangagwa's main rival Morgan Tsvangirai is suffering from cancer, which has helped expose divisions in his Movement for Democratic Change party as officials scramble to take over leadership of the party.

The economy is suffering acute shortages of foreign currency, increases in prices of basic goods, high unemployment and low levels of foreign investment, making it the biggest challenge for Mnangagwa.

At a function ahead of next week's World Economic Forum meeting in Davos, Mnangagwa said the extent of economic problems required Zimbabweans to work together as he promised to safeguard all investments in the country.

"All investments will be safe and secure in Zimbabwe. Foreign investors will be able to repatriate profits," he told a gathering of government officials and business leaders.

He said he was going to the Davos meetings, the such trip first by any Zimbabwean leader, to "dispel the perception" that Zimbabwe is "an isolated island".