US Defense Secretary Jim Mattis
© AP Photo/Jacquelyn MartinUS Defense Secretary Jim Mattis
US Defense Secretary Jim Mattis threatens Syria with a military action if the US finds hard evidence to back up the claims of another sarin attack in the country.

On February 2, Mattis told reporters that chlorine gas was known to have been weaponized in attacks in Syria. He further added that the US suspects the government of Syrian President Bashar Assad uses sarin nerve gas as a weapon on the battlefield.

"We are even more concerned about the possibility of sarin use," the defense secretary said. "I don't have the evidence, 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 would be ill-advised to go back to violating the chemical convention."

In April 2017, the US conducted a cruise missile strike against a Syrian airfield following reports about the alleged sarin use in the town of Khan Shaykhun.

"We're on the record and you all have seen how we reacted to that, so they would be ill-advised to go back to violating the chemical convention," Mattis said.

The new series of accusations that the Syrian government uses chlorine or even sarine against the so-called "rebels" and the "rebel-held" areas appared amid the rapid advance of the Syrian Arab Army against Hayat Tahrir al-Sham (formerly Jabhat al-Nusra, the Syrian branch of al-Qaeda) in the province of Idlib. So, Washington likely rushed to weaponize the al-Qaeda propaganda to oppose the defeat of the terrorist group in Syria.