France's deputy U.N. ambassador says an international team is blaming the Syrian government and Islamic State militants for chemical weapons attacks in the conflict-wracked nation during 2014 and 2015.

Alexis Lamek said the U.N. Security Council must take action against the perpetrators following Wednesday's report by the Organization for the Prohibition of Chemical Weapons-United Nations Joint Investigative Mechanism.

"It states clearly that the Syrian regime and Daesh have perpetrated chemical attacks in Syria, and in the case of the regime several cases are identified," Lamek said, using an Arabic acronym for the Islamic State group.

The joint body, known as the JIM, was set up by the Security Council last year and was investigating nine cases of alleged chemical weapons use.