PORT-AU-PRINCE — The United States told President Rene Preval on Thursday to pull his favored candidate out of Haiti's disputed presidential election race or risk losing US and international support.

The bold call, backed by Britain and France, came as the shock return of notorious former dictator Jean-Claude "Baby Doc" Duvalier threatened to muddy the political waters in the quake-hit and cholera-riddled Caribbean nation.

Susan Rice, the US ambassador to the United Nations, said Haiti must carry out the recommendations of international monitors who have called for Preval's protege Jude Celestin to be discarded from the delayed presidential run-off.

"Sustained support from the international community, including the United States, will require a credible process that represents the will of the Haitian people," Rice told a UN Security Council debate on Haiti.

"We urge the Haitian authorities to outline a very clear way forward that will lead promptly to the inauguration of a democratically-elected government."

Initial results in mid-December showed that opposition candidate Michel Martelly lost out to ruling party contender Celestin by less than 7,000 votes, sparking riots between rival factions that left at least five people dead.

Opposition candidates accused Preval of being in cahoots with the electoral commission to orchestrate massive fraud in favor of Celestin, a 48-year-old government technocrat who rarely spoke publicly in an uninspiring campaign.

After analyzing tally sheets, international monitors advised that the second and third finishers should be switched so Martelly would face Mirlande Manigat -- the 70-year-old former first lady who clearly topped the poll -- in the run-off.

More than a week after receiving the Organization of American States (OAS) report, Preval is yet to comment and the election commission insists it can only change the order if legal complaints from the candidates are upheld.

But the international community, which has pledged some 10 billion dollars to help Haiti rebuild after a devastating earthquake, does not want to just sit by and watch a protracted legal process ensue.

A year after the quake claimed more than 220,000 lives, much of the capital remains in ruins and a desperate populace is crying out for responsible leadership as the toll from an ensuing cholera epidemic nears 4,000.

"We urge the Provisional Electoral Council to implement the OAS recommendations," Rice said, calling for a "timely" timetable to hold the decisive second round.

UN peacekeeping chief Alain Le Roy told the Security Council he believed the electoral commission would announce definitive first round results on January 31 and aim to hold the second round mid-February.

Duvalier's surprise return on Sunday to the nation he fled in disgrace 25 years ago has only stoked further turmoil. He is yet to explain whether his motivation is political or personal and has endorsed no candidate.

Alex Dupuy, a respected Haiti expert Wesleyan University in Connecticut, saw nothing to be gained for Preval by Duvalier's return as the international pressure was not going to just go away.

"It's not going to reverse the decision of the OAS or the international pressure on Preval to accept that ruling and to allow the second round to be contested between Martelly and Manigat," Dupuy told AFP.

Memories of Duvalier's repressive 1971-1986 regime remain strong, and human rights groups have accused him and his late father of having presided over decades of unparalleled oppression and abuse.

On Tuesday, prosecutors charged him with corruption, embezzlement of millions of dollars from state funds and criminal association.

And in a new legal challenge, four Haitians, including a prominent journalist, filed criminal suits against him on Wednesday alleging crimes against humanity.

Rice also highlighted US concern over Duvalier's return.

"Given the continuing turmoil surrounding the November 28 election, the United States is concerned about the unpredictable impact that Duvalier's return may have on Haiti's political situation," she told the UN Security Council.

"My government is clear about Duvalier's notorious record of human rights abuses and corruption."

Duvalier's lawyer Reynold Georges said the former strongman planned to stay and clear his name.

Copyright © 2011 AFP