Iran on Sunday rejected French accusations of its forces assisting the Syrian regime against rebels, insisting it is for a political solution to the crisis in the strife-torn country.

"France is seeking to conceal its all-out interference in Syria's affairs which has led to human and financial losses," Iranian media quoted foreign ministry spokesman Abbas Araqchi as saying.

His remarks came after French Foreign Minister Laurent Fabius earlier on Sunday accused Iran of impeding a political solution to the Syrian crisis that has reportedly killed more than 90,000 people since it began in March 2011.

"We see, unfortunately, that day after day Iran's forces are strongly engaged on the side of Bashar-Assad, and this is certainly not the way to advance peace," Fabius said.

The Islamic republic is accused by Western and Arab countries which back rebels fighting its ally Assad of supplying weapons and sending military forces to the Syrian military. Iran denies these charges.

Tehran regards many Syrian opposition groups as "terrorists" backed by Western and Arab countries, but it urges talks to form a national reconciliation committee to end the conflict.

Fabius also reiterated his country's reservation over a role for Iran in next month's peace conference in Geneva, which aims to end the conflict by bringing together representatives from the Syrian regime and rebels.

"Given that Iran does not want a political solution, bringing along that country... risks preventing a political solution rather than favouring one," Fabius said.

France is hosting a three-way meeting on Monday with the United States and Russia to prepare for the Geneva conference.

On Sunday, Araqchi without mentioning the Geneva conference, said Iran "always supports reform and an end to the violence in Syria, and considers national dialogue as the solution to the crisis".

Moscow, an ally of Damascus, has requested that Iran be included in the talks regarding the Islamic republic as "a very important outside player".

Iran said on Tuesday that it is willing to attend the conference, arguing all influential parties must be included in the process for it to be a success.

Iran did not attend the previous Geneva meeting on the Syrian crisis in June 2012, which called for an immediate ceasefire. The United States and France had objected to its participation.