European Union foreign policy chief Javier Solana said on Monday Mugabe must be pressured to go after the United States and Britain said last week Mugabe’s departure was overdue.
The team of senior South African officials arrived on Sunday to assess the situation and ascertain what aid was needed, a department of foreign affairs spokesman said.
"They are there today and they are going to look at the humanitarian and food situation," the spokesman said.
South Africa, reacting to an unprecented call for international help from Mugabe’s government, said it would give further details of aid for Zimbabwe later this week.
Western countries in particular accuse Mugabe of ruining a once prosperous country and exposing Zimbabweans to famine and disease.
"I think the moment has arrived to put all the pressure for Mugabe to step down," the EU’s Solana told reporters ahead of a meeting of European foreign ministers in Brussels.
Solana said it was possible that the 27-nation bloc could decide at the meeting to add up to 11 officials to an already long list of Zimbabwean officials banned from travelling in Europe, but argued against any further sanctions.
"Everything that can be done has been done… The important thing is the political pressure now," he said.
British Prime Minister Gordon Brown has branded Mugabe’s government a "blood-stained regime" and said it was responsible for the cholera epidemic.
But Zimbabwe has accused Britain of using the epidemic to rally Western support for an invasion of the country.
Zimbabwe, isolated by Western countries under Mugabe’s increasingly authoritarian rule, has the highest rate of inflation seen in modern times — officially 231 million percent, but prices are actually doubling every 24 hours.
The currency is worthless and the $100 million Zimbabwean dollars people are limited to withdrawing from banks daily will only buy three loaves of bread.
The economic meltdown has left the health system incapable of coping with the cholera epidemic that it would once have prevented or treated effectively. The water system has collapsed, forcing people to drink from contaminated wells and streams.
Thousands of Zimbabweans are believed to cross the border, often illegally, into South Africa each day. A cholera centre has been set up in the South African border town of Musina.