PARIS: French President Francois Hollande said Tuesday that he's waiting for a decision from the US Congress on possible military action in Syria and insists France won't strike against Bashar Assad's regime alone.

The French leader and President Barack Obama have been the two most outspoken world leaders on the need to respond to a suspected chemical weapons attack Aug. 21 near Damascus that killed hundreds of people.

The French and US government have both laid out cases insisting Assad's regime was behind it, a claim Syria has denied.

At a news conference with German President Joachim Gauck, Hollande said the US vote, sought by Obama, and expected after Congress returns to session next week, about authorizing military action in Syria ''will have consequences on the coalition that we will have to create.''

He did not specify whether that meant a military coalition.

''A large coalition must therefore be created on the international scale, with the United States, which will soon take its decision, (and) with Europe ... and Arab countries,'' Hollande said.

If the Congress votes no, he said, France ''will take up its responsibilities by supporting the democratic opposition (in Syria) in such a way that a response is provided.''

The remarks came a day after France's government released an extract of intelligence gathered by two leading French intelligence agencies alleging that Assad's regime was behind the attack and at least two other, smaller-scale ones earlier this year.

Hollande added Tuesday that France confirmed the poison gas sarin was used in the attack last month.

The French parliament will debate the Syria issue Wednesday, but no vote is scheduled. France's constitution doesn't require such a vote on French military intervention until its lasts longer than four months, though some French lawmakers have urged Hollande to call one anyway.

He said Tuesday, ''We're not there yet.''

The US and France have argued that the alleged chemical weapons attack violates international conventions. Russia, which with Iran has been a staunch backer of Assad through the conflict, brushed aside Western evidence of an alleged Syrian regime role.

Hollande said he would speak to the French people ''once I have all the elements that can form the foundation of my decision, and I will carry out my responsibility in only one interest: That of France.''

The two-year civil war has left 100,000 dead in Syria.