France will carry out more strikes against the Syrian regime if the "red line" is crossed again, Foreign Minister Jean-Yves Le Drian warned on Saturday.
Speaking to French broadcaster BFMTV, Le Drian said there was "no doubt" about the suspected chemical attack in Douma.
"Chlorine was definitely used," he said.
Le Drian said: "If ... the red line is crossed again, there will be new strikes."
He said the objectives of the joint airstrikes had been met, adding: "I think the lesson will have been learnt."
The French strikes, involving 12 cruise missiles, fighter jets and warships, were President Emmanuel Macron’s first major military decision since taking office in May last year.
Macron had repeatedly vowed France would intervene if the Syrian regime crossed the "red line" and used chemical weapons in Syria.
The foreign minister said a large part of Syria’s chemical arsenal had been destroyed, and all French jets returned safely.
Le Drian insisted it was important to continue talking to Russia, and that Macron’s trip to St. Petersburg at the end of May would go ahead as planned.
"This action was proportionate and targeted, it was not aimed at Assad’s allies nor at the civilian population," Le Drian said earlier in a joint televised statement with Defense Minister Florence Parly.
Parly said "Russians were warned beforehand", adding that France does "not seek confrontation, and we refuse any possibility of military escalation".
The U.S., U.K. and France jointly launched strikes early on Saturday targeting the Assad regime's alleged chemical weapons research center near Damascus, a chemical weapons warehouse and a command center linked to chemical weapons located west of Homs, U.S. Joint Chiefs of Staff Chairman Joseph Dunford said at a joint news conference with American Secretary of Defense James Mattis.
The White Helmets, a civil defense agency, blamed the Assad regime for an alleged chemical attack earlier this month, which it said killed 78 civilians and injured hundreds of others.
Report on regime attack
Also on Saturday, the French Foreign Ministry released a seven-page long assessment of the alleged chemical attack in Syria's Douma on April 7, which concluded that there was no other plausible explanation than a chemical attack coordinated by the Syrian military.
The assessment is based on technical analyses of open source information and declassified intelligence obtained by French services. It also used an evaluation of publicly available information from non-governmental organizations and other sources as well as unspecified French intelligence.
"On the intelligence collected by our services, and in the absence to date of chemical samples analysed by our own laboratories, France considers, beyond possible doubt, a chemical attack was carried out against civilians at Douma ... and that there is no plausible scenario other than that of an attack by Syrian armed forces," the report said, adding:
"After examining the videos and images of victims published online, they [intelligence services] were able to conclude with a high degree of confidence that the vast majority are recent and not fabricated."
The French intelligence report said no deaths from mechanical injuries were visible and all symptoms were characteristic of a chemical weapons attack, particularly choking agents and organophosphorus agents or hydrocyanic acid.
"Reliable intelligence indicates that Syrian military officials have coordinated what appears to be the use of chemical weapons containing chlorine on Douma, on April 7," it said.
The ministry said the assessment "will be updated as we collect new information".
This article has been adapted from its original source.