The U.S. has no evidence to confirm reports from aid groups and others that the Syrian government has used the deadly chemical sarin on its citizens, Defense Secretary Jim Mattis said Friday.
American officials emphasized on Thursday that the United States was seeking a new way to hold chemical weapons-users accountable and wanted cooperation from Russia, Assad's patron, in pressuring him to end the attacks.
However it was "highly likely" that Syria had stockpiled some of its weapons after the 2013 intervention, the Trump administration officials said in a briefing reported by 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. "The regime appears to have weaponized chlorine again", Mattis told Politico, "but we are even more concerned about the possibility of sarin use". "What I am saying is that other groups on the ground - NGOs, fighters on the ground - have said that sarin has been used, so we are looking for evidence".
"They think they can get away with it if they keep it under a certain level", an official said.
Since last April, Syria has continued to use chemical weapons, the officials said.
But there have been repeated reports of smaller chemical attacks on civilian areas.
European Central Bank monetary stimulus still needed to push up inflation -Draghi
Stimulus withdrawal has been much discussed in markets because the eurozone economy is growing strongly. Its rate of minus 0.4 percent on deposits it takes from commercial banks was also unchanged.
Despite Damascus agreeing to destroy its 1,300-tonne stockpile of industrial munition following a US-Russian deal after the Ghouta attack in 2013, United Nations inspectors found evidence of an ongoing chemical weapons programme in the country.
If left unchecked, the U.S. officials added, Assad could use small chemical attacks in the hopes to redress the power imbalance in rebel-held areas as an "instrument of terror".
The bloodshed came a day after the latest suspected chlorine attack by the regime of President Bashar al-Assad on Ghouta, which has been besieged by government forces since 2013. "Using military force is something that is still considered".
Years of efforts by two USA presidents have failed to end the reports on chemical-weapons use in Syria.
Eastern Ghouta is the last remaining rebel stronghold near the capital, Damascus, and has been under a government siege since 2013. The Islamic State militant group continues to use them, they said, although the militants' arms are said to be more rudimentary.
Syria's war has killed more than 340,000 people and displaced millions since it began in March 2011 with the brutal repression of anti-government protests.