Iran bears a "heavy responsibility" in conflicts in the Middle East, especially in Gaza, French Foreign Minister Laurent Fabius said Wednesday.

Speaking specifically of Gaza, where a week of violence has claimed more than 140 lives, Fabius said: "There are long-range weapons up to 75 kilometers (45 miles) and these are Iranian weapons. Iran bears a heavy responsibility.

French Foreign Minister Laurent Fabius reiterated on Tuesday that France will not interfere in Lebanon's domestic affairs, but fully supports its stability.

“France does not interfere in Lebanon's internal affairs, but we fully back stability in Lebanon,” he said after holding talks with Prime Minister Najib Miqati at the French Foreign Ministry in Quai d'Orsay in Paris.

Pressure piled up on France on Tuesday to reform its economy following a critical debt downgrade from ratings agency Moody's but initial market reaction was muted and the government stood by promises that change is underway.

Moody's is now the second of the three major ratings agency to cut France's top-notch triple A rating, noting it down to "Aa1" with a warning that a further downgrade could be on the cards.

Prime Minister Najib Miqati stressed that he is ready to step down if the March 14 coalition agrees to participate in a national unity cabinet, An Nahar newspaper reported on Tuesday.

“I agree on the formation of a new government if the resignation of my cabinet is a solution to the current political crisis,” french parliamentary sources told the daily.

France ended its combat mission in Afghanistan on Tuesday, withdrawing troops from a strategic province northeast of Kabul as part of a speeded-up departure from the war-torn country.

Paris has said all French combat soldiers will leave the country next month, two years before allied nations contributing to the 100,000-strong International Security Assistance Force (ISAF) led by the United States are due to depart.

A young French-Turkish student appeared in court again on Monday accused of links to an outlawed far-left extremist group in a case which has sparked outrage among rights group.

Sevil Sevimli, a 20-year-old exchange student, was arrested in Turkey after joining a May Day parade in Istanbul and went on trial in September on charges that risk up to 32 years in prison.

Prime Minister Najib Miqati stressed on Monday the need for France's support for Lebanon, while highlighting the strength of the historic ties between the two countries.

He said: “The situation in southern Lebanon, Special Tribunal for Lebanon, and the Lebanese government's policy of disassociation from the Syrian crisis will ensure Lebanon's stability.”

Thousands of Catholics and other opponents of French government plans to legalise gay marriage and same-sex adoption marched in Paris on Sunday, a day after more than 100,000 turned out across France for the cause.

The rally, organised by conservative Catholic group Civitas, was marred by accusations that protesters had roughed up journalists and topless counter-protesters partially dressed as nuns.

The battle to succeed former president Nicolas Sarkozy at the helm of France's main opposition party, the UMP, was left undecided early Monday after both candidates claimed victory amid allegations of ballot rigging.

Jean-Francois Cope, the party's populist secretary-general, claimed a clear win while former prime minister Francois Fillon said he believed he had edged the contest subject to confirmation by the electoral commission which oversaw the poll.

French Foreign Minister Laurent Fabius said on Sunday a ceasefire between Israel and Gaza militants was an urgent necessity and France was willing to help broker a truce.

"War is not an option, it is never an option," he told journalists in Tel Aviv. "There are two key words: urgency and ceasefire," he said.