Nauert said in a press briefing on Friday that the US has proof that the Syrian government was behind this attack, and will "continue to gather information and further assess it", Xinhua news agency reported.
"I can tell you this. Syria's responsible. We are all in agreement," she said. "We can say that the Syrian government was behind this attack."
However, she refused to show the evidence, saying the thing was "sensitive."
"The UK, I'm confident in saying, had absolutely nothing to do with it," she added. "It is the assessment of the US government, the British government, the French government."
The Syrian government has denied the allegations and called the reports fake news that the West uses to justify attacking the country.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)