|Aristide has been removed from power twice, the first in 1991 when he was toppled in a coup detat [EPA]
Haiti's former president is set to return home, ending seven years in exile in South Africa, South African officials have said.
Jean-Bertrand Aristide's diplomatic passport was delivered last month, and South Africa's cabinet minister, Collins Chabane, said on Thursday "we can't hold him hostage if he wants to go".
The announcement came as Barack Obama, the US president, made last-ditch efforts to prevent his return over concerns that Aristide's presence in Haiti could disrupt elections to be held on March 20.
A White House spokesman said Obama recently called Jacob Zuma, his South African counterpart, to discuss the matter but the South Africans apparently could not delay Aristide's return.
"The United States, along with others in the international community, has deep concerns that president Aristide's return to Haiti in the closing days of the election could be destabilising," Tommy Vietor, the National Security Council spokesman, said in Washington.
"President Obama reiterated ... his belief that the Haitian people deserve the chance to choose their government through peaceful, free, and fair elections March 20."
South African officials, speaking on condition of anonymity because they were not authorised to make the official announcement, said Aristide would leave immediately after addressing reporters at a Johannesburg airport.
According to the South African Press Association, Chabane said the government cannot be held responsible for whether Aristide stays or leaves.
"What I should stress is that we are not sending former president Aristide to Haiti. He was given the passport by the government of Haiti and we can't hold him hostage if he wants to go," Chabane was quoted as telling a news conference.
Actor to escort Aristide
Chabane's comments came as Danny Glover, an actor, arrived in South Africa to try to escort the ousted leader home.
Glover, the chair of TransAfrica social justice forum, asked why Haiti's former president, Jean-Claude Duvalier, could return home unhindered and not the twice democratically elected Aristide.
"People of good conscience cannot be idle while a former dictator is able to return unhindered while a democratic leader who peacefully handed over power to another elected president is restricted from returning to his country by external forces," Glover wrote on the TransAfrica Forum website.
On Monday, US state department spokesman Mark Toner acknowledged Aristide's right to go back to Haiti, but said returning this week "can only be seen as a conscious choice to impact Haiti's elections".
Aristide, who emerged as a leading voice for Haiti's poor in a popular revolt that forced an end to the Duvalier family's 29-year dictatorship, remains Haiti's most popular politician though he has been in exile since 2004.
He has said he will not be involved in politics in Haiti and wants to lead his foundation's efforts to improve education in the impoverished Caribbean nation devastated by last year's catastrophic earthquake.
It would be the second return from exile for Aristide, who was first ousted by a military coup in 1991. Bill Clinton, the former US president, returned him to power in 1994 following a US military intervention that forced out the military regime.
Haiti held elections last November but they were marred by fraud and ended with no clear winner. One of the three main contenders, who finished third, said he was rigged out of a second run-off place.