At best the visit is ill-timed. President Mandela honoured the leader of the country the United States accuses of sponsoring international terrorism with a 21-gun salute. Meanwhile Thabo Mbeki, the deputy president, is completing a high-profile, week-long visit to the US to woo investors.
At worst the visit, during which an oil storage deal worth 750m rand (pounds 107m) a year to South Africa will be discussed, reflects a contradictory position. It also reinforces criticism that South Africa has no coherent foreign policy and that its foreign ministers possess little political acumen.
There has already been strong criticism of President Mandela's dogged determination to follow a "two China policy" - pursuing strong links with both China and Taiwan - and his stubborn loyalty to old allies such as Libya and Cuba. Critics say South Africa's international openness amounts to no more than a naive desire for the entire world to love it.
In diplomatic circles Alfred Nzo, the foreign minister, is held responsible for what many see as a poor foreign relations start. Among the many criticisms of the man nicknamed Nzozzzzzzz are that he lacks experience and dynamism.
"We all sit around scratching our heads on the Libya question," said one diplomat. "Why this debt of loyalty to Libya when it actually supported the Pan-Africanist Congress."
The foreign affairs department is taking the criticism - particularly from its own MPs - seriously.
But at a two-day foreign affairs seminar this week officials said the row over Iran ignored the vast trade deficit between the two countries.
"We import R4bn of oil from Iran and only export R300m of goods to the country," one said. "It's a dramatic imbalance."
Offending the Americans had to be weighed against the national interest. Everything the new regime did came under the spotlight. Yet it was only one stop on a six-country tour by the Iranians. "We are not exactly supping at a table where no one else has sat."
Officials also complain that critics forget the conditions from which the new democracy emerged. Privately they admit a foreign policy weakness may be the country's attempt to be all things to all people. "Perhaps the real world is a lot tougher than we imagined."
While the new South Africa was criticised for its apparent reluctance to play a greater role in regional conflicts, there was too little recognition of the heavy legacy of the previous government, which had intentionally destabilised the region. The new South Africa had to be involved but avoid becoming a reviled "big brother".
Greg Mills, director of the South African Institute of International Affairs, has called the department's new discussion document on foreign policy "an ambitious and at times confusing wish list" and concluded that a combination of weak foreign policy and the high international standing of President Mandela has led to a situation where foreign profile masquerades as foreign policy.
Yesterday he was a little kinder. Critics, he said, were ignoring South Africa's regional successes, including its revitalisation of the 12-member South African Development Community, which had become no more than a talking shop.
They also forgot that in the past two years the foreign affairs department had seen a massive expansion abroad, from a mere 30 representatives during apartheid to the current 120.
There had been disasters, such as Mr Nzo's comments this year on the Lockerbie bombing, supportive of Libya. And a large political donation from Taiwan to the ANC in the run up to the elections.
If the deal with Iran goes ahead, despite the US's condemnation and criticism at home that it would contravene South Africa's commitment to human rights, it may actually reflect a growing maturity and independence.
Dr Mills says the country's foreign policy is still more rooted in idealism than most others, but decreasingly so. The current foreign policy calculation should be made on the basis of economic benefit against the level of US wrath. South Africa's priority has to be the prosperity of its people.
"Foreign policy is about making hard choices. I think the US is big enough to recognise that."