Speaking on TF1 television, Mr Macron said "we have proof that chemical weapons were used, at least chlorine" in recent days by Syrian President Bashar Assad's government. He didn't elaborate on exactly what that proof is.
Political opponents had criticized Macron for drawing a red line over chemical attacks after the unfortunate precedent set by former U.S. President Barack Obama, who had put himself in a tough spot with a similar ultimatum in 2012.
"The President has been clear that he wants United States forces to come home as quickly as possible", spokeswoman Sarah Sanders said. "Could be very soon or not so soon at all!"
He said: "France will in no way allow an escalation or anything that would harm regional stability, but we cannot allow regimes that believe they can act with impunity to violate global law in the worst possible way".
"We can not tolerate the recurring use of chemical weapons, which is an immediate danger for the Syrian people and our collective security", a statement from the Elysee presidential office said.
The Russian government has indicated that it would react if its forces felt threatened by a possible western strike against the Assad regime.
Saying that public anger "doesn't stop me", Macron said he would "go to the end" of the train reforms, meant to prepare the national SNCF railway to open to competition.
The French leader accused Russian Federation of "systematically building" the global community's inability to implement 2013 deal on Syria's chemical weapons and said Moscow is an "accomplice" of Syrian regime.
Netflix overseas sales set to overtake US
If you're interested, the company has also posted the video of its earnings Q&A call for the quarter, which can be viewed below. Finally, Tybourne Capital Management HK Ltd. boosted its holdings in shares of Netflix by 43.4% during the 4th quarter.
Goldman Sachs ActiveBeta Europe Eq ETF (GSEU) Rises 0.48% for April 16
Quantbot Techs L P holds 0.29% in The Goldman Sachs Group, Inc . (NYSE:GS) for 1,300 shs. (NYSE:GS) or 12,272 shs. Davide Campari Milano SpA (OTCMKTS:DVDCY) traded up 0.0000% during mid-day trading on Friday, hitting $5.5975.
Significant ice, rain likely with weekend storm
Hydro One said it has crews ready to respond to outages 24/7, and additional resources are on standby this weekend. Surfaces such as highways, roads, walkways and parking lots will become icy, slippery and extremely hazardous.
Macron kept up the drumbeat for likely war with his claim of evidence that chemical weapons were used in the attack, although he did not elaborate.
"I have ordered the French army to intervene tonight as part of the worldwide operation in coalition with the United States and Britain directed against the clandestine chemical arsenal of the Syrian regime", he said.
Macron has long called the use of chemical weapons in Syria a "red line" that would trigger French retaliation.
Mattis said he hoped that experts from the Organisation for the Prohibition of Chemical Weapons would soon be granted access to Douma, but he noted that any possible inspection would not be able to establish who was responsible for the incident.
Amid the talk of military action, the Kremlin, a close ally of Assad, countered that more "serious approaches" were needed to combat the crisis.
If confirmed, the town's seizure would mark the last stage of Assad's takeover of the rebel-held enclave of eastern Ghouta.
The veto had prevented a "united" front on putting in place a mechanism "to prevent the regime being a repeat offender", Macron said. Syria's official SANA news agency reported.
Asked if and when Syrian facilities would be targeted, Macron replied: "When we decide, and we will have to verify all the information".