Donors have made clear they will only provide a large aid package once Zimbabwe's new unity government meets key conditions, including enacting economic reforms.
Mugabe and opposition leader Morgan Tsvangirai, the country's prime minister, entered into a unity government in February.
The move came after disputed elections in early 2008 led to an outbreak of violence and nearly a year of political deadlock.
The government is now faced with tackling a financial crisis that has led to food shortages and the world's highest inflation rate, as well as a cholera epidemic partially blamed on the collapse of the country's health and sanitation systems.
Zuma said the creation of Zimbabwe's unity government is only a starting point for the country's stabilisation.
"You cannot say it has stabilised, but it has entered a phase of stabilisation politically."
Zuma, the leader of South Africa's African National Congress (ANC), is a favourite to win the country's presidential elections in April.