France has proof that the Syrian government launched chlorine gas attacks and has crossed a line that could prompt French airstrikes, President Emmanuel Macron said Thursday.

Macron did not specify whether France is planning military action against Syrian President Bashar Assad's government. He said he has been talking regularly this week with U.S. President Donald Trump about the most effective response.

The U.S., France and Britain have been consulting about launching a military strike. Trump tweeted Wednesday that missiles "will be coming" and on Thursday tweeted that an attack "could be very soon or not so soon at all!"

Speaking on TF1 television, Macron said that France would not tolerate "regimes that think everything is permitted."

He previously said any French action would target Syria's chemical weapons abilities.

Syrian opposition activists and medics say a suspected gas attack last week in Douma killed more than 40 people. The Syrian government has denied the allegations.

Macron's office and the French military aren't commenting on pending plans. A military operation would be a big deal for Macron, his first military action as president, at a time of heightened domestic tensions over labor law changes.

Macron doesn't need parliamentary permission to launch an operation.

French forces have not directly targeted Syrian government sites before, but France has supported rebel forces since early in the fighting that began in 2011.

Geopolitics specialist Dominique Moisi, a senior adviser at the Montaigne Institute think tank in Paris, said "we have said that we were not allowing the use of chemical weapons, that this was a red line ... Not to react is to prove to the rest of the world that what we say does not matter."

Moisi stressed the "risk of escalation" of the conflict amid increasing concerns about a U.S.-Russia proxy war.

"So striking at Syria is not a good solution, but doing nothing after the use of chemical weapons is even worse," he said.

In London, British Prime Minister Theresa May summoned her Cabinet back from vacation Thursday to discuss military action against Syria.

May has indicated she wants Britain to join in any U.S.-led strikes in response to the attack in Douma. She has said all the indications" are that Assad's forces were responsible and the use of chemical weapons "cannot go unchallenged."

Chancellor Angela Merkel said Germany won't participate in possible military action in Syria, but supports sending a message that the use of chemical weapons is unacceptable, following a phone call Thursday with Macron.

France already has some 1,100 troops involved in its Operation Chammal, created in 2014 to fight Islamic State extremists in Iraq and extended in 2015 to Syria, as part of the U.S.-led coalition. Multiple Islamic State retaliatory attacks have targeted French soil, including just last month.

French warplanes operate out of French bases in Jordan and Al Dhafra in United Arab Emirates. France also has a naval base in Abu Dhabi, and an aviation center in Qatar at the U.S. air base at Al Udeid. France has 650 troops based in the United Arab Emirates overall.

In addition, a French frigate is stationed off of Lebanon in international waters.

In Syria, French warplanes carried out 23 sorties in late March and early April but fired no strikes, as part of support for Syrian opposition forces fighting in the last pockets of IS control.


Chris Den Hond in Paris, Jill Lawless in London, Geir Moulson in Berlin contributed to the story;