FILE PHOTO: A U.N. chemical weapons expert, wearing a gas mask, holds a plastic bag containing samples from one of the sites of an alleged chemical weapons attack in the Ain Tarma neighbourhood of Damascus, Syria August 29, 2013. REUTERS/Mohamed Abdullah/File Photo

PARIS (Reuters) - France said on Friday it was “deeply concerned” that Syria’s government was flouting its pledges to stop using chemical weapons and Paris was working with its partners to shed light on recent suspected toxic gas attacks.

Senior U.S. officials said on Thursday that the Syrian government may be developing new types of chemical weapons, and U.S. President Donald Trump is prepared to consider further military action if necessary to deter chemical attacks.

Rescue workers and medical groups working in the rebel-held enclave of Eastern Ghouta, near to Damascus, have accused government forces of using chlorine gas three times over the last month, including on Thursday morning.

French foreign ministry spokeswoman Agnes Von der Muhll said that reports from the OPCW, the global chemical weapons watchdog, indicated that Damascus had not met commitments made in 2013 to fully abandon its chemical stockpiles and was not conforming with international conventions banning their use.

“This gives rise to our deepest concern. France does not accept that the convention prohibiting chemical weapons be challenged,” von der Muhll told reporters in a daily online briefing.

President Bashar al-Assad’s government denies using chemical weapons, which it agreed to destroy in 2013 under an agreement brokered by Russia and the United States.

“We are actively working with our partners on this issue and on all reports of new chemical attacks in Syria,” von der Muhll said.

A deadly sarin attack on a rebel-held area in April 2017 prompted Trump to order a missile strike on the Shayrat air base, from which the Syrian operation is said to have been launched.

French President Emmanuel Macron has said that Paris could launch unilateral air strikes against targets in Syria if a new chemical attack took place, although he has since said he would coordinate any action with Trump.