Activists and aid groups say dozens died in the assault on Douma, the last rebel stronghold in eastern Ghouta, which has been subjected to intensive bombing by Syria’s Russian-backed regime of President Bashar al-Assad.
The U.S. has blood and urine samples from the area that have tested positive for chemical weapons, according to two U.S. officials familiar with the intelligence.
The samples suggested the presence of both chlorine gas and an unnamed nerve agent, two officials said. Typically, such samples are obtained through hospitals and collected by U.S. or foreign intelligence assets on the ground. The officials said they were “confident” in the intelligence, though not 100 percent certain.
Assad is known to have stocks of the nerve agent sarin, and has previously used a mixture of chlorine and sarin in attacks, according to U.S. officials.
Lavrov urged more diplomatic contacts over the issue and said Russia was open to further telephone contact between Trump and President Vladimir Putin.
“Diplomatic methods need to be used, which do not include ultimatums and threats,” he said.
Earlier this week, a Russian diplomat pledged that U.S. missiles would be shot down and American military assets targeted in the event of strikes targeting Syria.
The White House said Thursday that Trump has not made any final decisions regarding a U.S. response after convening with national security advisers but that a decision would be made “soon.”
The U.S. ambassador to Britain said Friday that Trump had spoken overnight with Prime Minister Theresa May about “the need for a joint response.”