France's former right-wing president Jacques Chirac will vote for the Socialist Francois Hollande in Sunday's first-round presidential vote, a newspaper Tuesday quoted a source close to him as saying.

French historian Jean-Luc Barre, who helped Chirac write his memoirs, told Le Parisien newspaper the former president had not been joking when he said he would back Hollande, who has spent most of his political life in Chirac's hometown of Correze.

President Nicolas Sarkozy formally admitted Saturday that France failed in its duty towards the Algerian loyalists who fought on Paris' side in their country's war of independence.

Around 60,000 pro-French Algerians, known as "harkis", came to France after the war, but approximately as many again were abandoned to face bloody reprisals in Algeria at the hands of their pro-independence countrymen.

Firebrand leftist Jean-Luc Melenchon gathered thousands of supporters in Marseille on Saturday, on a weekend of rallies before the first round of France's presidential vote.

Communist-backed Melenchon, who has shaken up the vote with a surge in the polls, will be hoping for a repeat of rallies in Paris and Toulouse that were the biggest of the campaign, drawing tens of thousands onto the streets.

The U.N. Security Council will vote Saturday on a Western-drafted resolution allowing a ceasefire observer mission in Syria even though Russia's support is in doubt.

The United States called for the vote after a second day of wrangling with Russia over security guarantees for the first 30 unarmed military monitors who U.N.-Arab League envoy Kofi Annan wants in Syria early next week.

Talks between Iran and six world powers in Istanbul on Tehran's nuclear program, the first in 15 months, began Saturday in a "positive atmosphere," a European Union spokesman said.

"There is a positive atmosphere. ... There is a desire for substantive progress," Michael Mann, spokesman for EU foreign policy chief Catherine Ashton, told reporters.

A Lebanese-Canadian university professor accused of a 1980 bombing of a Paris synagogue that killed four people will appeal an order to extradite him to France, his lawyer said Friday.

Canada's justice minister on April 4 signed an order to send Hassan Diab to France after a Canadian court in June 2011 approved his extradition despite its concerns the case is "weak."

Western nations and Russia on Friday put forward rival U.N. Security Council resolutions on sending ceasefire observers to Syria as they wrangled over conditions for the mission.

The dispute after two days of tough negotiations means no vote is likely until Saturday on any final resolution which would allow an advance party of 30 unarmed military observers to go to Syria next week.

France has "elements of evidence" that crimes against humanity have been committed by the Syrian regime, French Foreign Minister Alain Juppe said Thursday.

"France has gathered a certain number of elements of evidence which would enable us if the time comes, notably at the U.N., to take it before the international courts, because crimes against humanity have been committed," he told reporters on the sidelines of a meeting of G8 ministers.

Lebanon can file a complaint with the U.N. Security Council against Syria over the killing of Lebanese cameramen Ali Shaaban, diplomatic sources said Wednesday.

The sources told al-Mustaqbal daily however that the problem lies in the lack of a political decision to file such a complaint.

France said on Tuesday that Syria was not implementing a U.N. and Arab League-backed peace plan after Damascus said it had started pulling troops out of certain provinces.

The Syrian claim was "a new expression of a flagrant and unacceptable lie" that "shows a degree of impunity against which the international community absolutely must act," foreign ministry spokesman Bernard Valero said.