PARIS • Two dozen countries agreed to push for sanctions against perpetrators of chemical attacks in Syria, with US Secretary of State Rex Tillerson saying Russia "ultimately bears responsibility" for such strikes.

Twenty-four nations on Tuesday approved a "partnership against impunity" for the use of chemical weapons, just a day after reports they were used in an attack that sickened 21 people in rebel-held Eastern Ghouta. Mr Tillerson said that attack was suspected to involve chlorine.

"Whoever conducted the attacks, Russia ultimately bears responsibility for the victims in East Ghouta and countless other Syrians targeted with chemical weapons since Russia became involved in Syria," he said after the international meeting in Paris, and ahead of further talks with ministers from several countries on ending the conflict.

"There is simply no denying that Russia, by shielding its Syrian ally, has breached its commitments to the US as a framework guarantor" overseeing destruction of Syria's chemical weapons, as agreed in September 2013, he added.

Despite its pledge to destroy such weapons, the Syrian regime has been repeatedly accused of staging chemical attacks, with the United Nations among those blaming it for an April 2017 sarin gas attack on the opposition-held village of Khan Sheikhun which left scores dead.

There have been at least 130 separate chemical attacks in Syria since 2012, according to French estimates, with the Islamic State in Iraq and Syria also accused of using mustard gas in Syria and Iraq.

Russia twice used its UN veto in November to block an extension of an international expert inquiry into chemical attacks in Syria, to the consternation of Western powers.

Russia's UN ambassador Vassily Nebenzia on Tuesday rejected Mr Tillerson's accusations, calling for a "truly impartial" international investigation of the chemical attacks.

Moscow, backed by Iran and Turkey, has organised talks in Sochi next week aimed at ending the brutal and multifaceted civil war.

Those efforts are running parallel to talks overseen by the UN, with the latest round due in Vienna today and tomorrow. The talks have so far failed to make progress in ending a war that has left over 340,000 dead.

At Tuesday's meeting, 24 out of 29 countries attending committed to sharing information and compiling a list of individuals implicated in the use of chemical weapons in Syria and beyond.

These could then be hit with sanctions and entry bans as well as criminal proceedings at national level.

Ahead of the meeting France announced asset freezes against 25 Syrian companies and executives, as well as French, Lebanese and Chinese businesses accused of aiding regime use of chemical weapons.

"The criminals who take the responsibility for using and developing these barbaric weapons must know that they will not go unpunished," said French Foreign Minister Jean-Yves Le Drian, who chaired Tuesday's meeting. "The current situation cannot continue."

Meanwhile, Syria also denied yesterday carrying out chemical attacks against rebel-held areas, calling recent accusations "lies".

"Syria condemns all the lies and allegations by the American and French foreign ministers," a Foreign Ministry official told state news agency SANA.

AGENCE FRANCE-PRESSE