PARIS — Russian President Vladimir Putin’s claim that rebels were behind the Aug. 21 chemical attack in Syria “is not the reality,” French Foreign Minister Laurent Fabius said.

“The reality is clear: there was a chemical massacre, it’s the regime of Bashar al-Assad that has the chemical weapons and that gave the order,” Fabius said in an interview Thursday on RTL Radio.

Putin said in a New York Times opinion article published late Wednesday that the attack was the work of the opposition. The U.S., French, and British governments have released intelligence reports blaming the regime for the attack, which they say killed more than a 1,400 civilians.

“It’s a version the Russians have developed for a long time, without any credibility,” Fabius said.

Fabius said “all options remain on the table” for Syria, and it’s the “great firmness” of the U.S. and the French threat of military strikes that led to the Russian proposal to put Syria’s chemical weapons under international control.

Any such plan must be “rapid, credible, and verifiable,” Fabius said in the radio interview. He said destroying a stockpile as large as Syria’s “takes an immense amount of time.”