Haiti's electoral authorities will release results next week from the country's disputed presidential election and set a date for a runoff vote in signs a protracted electoral impasse may be easing.

The results from the first-round vote will be made public on Wednesday with a runoff set to take place on March 20, Haiti's electoral council said in a statement late Friday.

Political uncertainty has gripped Haiti, the Western Hemisphere's poorest country, since a chaotic November 28 presidential vote that was marred by fraud allegations and street protests.

Official preliminary results showed a government-backed candidate, Jude Celestin, would advance to a second-round vote against former first lady Mirlande Manigat.

But President Rene Preval, who has faced accusations of rigging the first-round vote results, is under intense pressure from the U.S. government and other Western powers to accept a report by Organisation of American States experts that recommends dropping Celestin from the runoff in favour of another candidate.

The recommendation followed a review by OAS electoral experts of the contested results in the earthquake-battered Caribbean country.

On Wednesday, Haiti's ruling party said it had agreed to pull Celestin from the elections, but he has not yet formally withdrawn.

Michel Martelly, a popular musician who finished a close third in the November vote, has warned his supporters will take to the streets if he is not included in the runoff.

The new vote schedule came ahead of a planned visit by U.S. Secretary of State Hillary Clinton, who is expected to arrive in Haiti on Sunday.

Clinton will meet with Preval and the Haitian candidates to discuss the election and reconstruction efforts a year after a devastating earthquake hit the country.