Iran’s foreign minister on Sunday condemned the use of chemical weapons and appeared to offer to mediate in the Syria crisis.

Iran's foreign minister on Sunday condemned the use of chemical weapons and appeared to offer to mediate in the Syria crisis.

"We condemn chemical weapons," Ali Akbar Salehi told Germany's Der Spiegel newsweekly in an interview published on Sunday.

Iran, a strong Damascus ally, was itself a victim of chemical warfare during its conflict with Iraq in the 1980s, Salehi recalled.

Tehran is "categorically against all weapons of mass destruction", he said.

Iran is currently facing criticism over its civil nuclear program which the West suspects is a front for developing weapons.

Damascus government accused militant opposition groups of using chemical weapons against Syrian people and called for a UN probe to investigate the file.

US Secretary of State John Kerry on Friday said there was "strong evidence" the Assad’s forces had used chemical weapons against militiamen, but the UN said there was no incontrovertible evidence yet.

With fears the war, now in its third year, could turn even deadlier, diplomatic efforts have been ramped up, with Russia and the US last week renewing joint efforts to find a solution to the crisis.

Salehi told Spiegel his country was willing to take part in an international conference on Syria proposed by the US and Russia, which could take place later this month.

Iran could "launch talks between Syria's government and opposition", he said, marking a step towards greater involvement for Iran which has previously called for talks between Syrian insurgents and the government.

Salehi said he was "confident" that progress was being made in the conflict, which is estimated to have killed 70,000 and displaced millions more internally and in neighboring countries.