AP
Russian Foreign Minister Sergei Lavrov and French Foreign Minister Laurent Fabius set out their countries' opposing views following talks in Moscow, one day after the investigators confirmed the deadly nerve agent sarin was used in the attack.
"We have very serious grounds to believe that this was a provocation," Lavrov said of the attack, which the United States has said killed more than 1,400 people in rebel-held areas.
Lavrov, whose country has been the Syrian government's most important ally in the civil war, said there had been "many provocations" by the rebels fighting President Bashar al-Assad's government and added: "They were all aimed, over the last two years, at provoking foreign intervention."
He said the U.N. investigators' report proved that chemical weapons had been used but that "there is no answer to a number of questions we have asked," including whether the weapons were produced in a factory or home-made.
Speaking alongside Lavrov at a joint news conference after their talks, Fabius said the report was convincing.
"When you look at the amount of sarin gas used, the vectors, the techniques behind such an attack, as well as other aspects, it seems to leave no doubt that the (Assad) regime is behind it," Fabius said.
(Reporting by Alissa de Carbonnel and Gabriela Baczynska in Moscow and John Irish in Paris, Writing by Steve Gutterman, Editing by Timothy Heritage)