U.S. Ambassador Kenneth Ward levied the accusation against Russian Federation during a closed-door meeting at the Organisation for the Prohibition of Chemical Weapons.
"The speed with which we acted was essential in co-operating with our partners to alleviate further humanitarian suffering and to maintain the vital security of our operations", she said.
According to officials, they have even prepared for a direct cyber-attack on United Kingdom national infrastructure, pointing out that they had "pre-positioned" inside Russian computer networks and would launch a retaliatory attack if the United Kingdom was targeted.
"It is our understanding the Russians may have visited the attack site".
He said Moscow was "spreading conspiracy theories and misinformation" to undermine the integrity of the OPCW's fact-finding mission to Syria.
The Russian foreign minister told the BBC: "There is no proof that on April 7 chemical weapons were used in Douma".
Around 75 people, including children, were killed in the Douma assault, United Kingdom officials said, while 500 people were treated in the attack's aftermath with symptoms consistent with chemical weapons exposure, the World Health Organization reported. "All the evidence they quoted was based on media reports and social media", he said.
"They are hard for us, but will do more damage to the U.S. and Europe", RIA news agency quoted Serebrennikov as saying.
"It's not something we're going to tolerate and they've got to make a decision", she added.
Mrs May's decision to launch air strikes without parliamentary approval has led to criticism from MPs.
After Britain and France joined the United States in missile salvoes meant to cripple Syrian chemical arms facilities and prevent their further use, Western leaders sought to emphasis diplomacy, with an European Union foreign ministers meeting in Luxembourg.
Minister Blok again in Syria.
Russian diplomat Dmitry Polyanskiy said "all the obstacles" for the OPCW mission were the result of the US, UK and French "aggression" and the possibility of further strikes.
And shadow attorney general Baroness Chakrabarti questioned the Government's justification for the airstrikes, telling BBC Radio 4's Today programme: "You can't use force under global law just to punish Syria for bad behaviour".
"You have to actually be using urgent, necessary and proportionate force".
One of the three sites hit was the Barzeh complex, which the United States says was a centre for development, production and testing of chemical and biological weapons, although Syria denies this.
"I would like to believe that we will not see a day that is worse than today", he said.
"Without UN authority it was again a matter of the USA and British governments arrogating to themselves an authority to act unilaterally which they do not possess".
It seeks answers from Syria on gaps in its chemical weapons declaration to the Organization for the Prohibition of Chemical Weapons.
"For we can not allow the use of chemical weapons to become normalised - either within Syria, on the streets of the United Kingdom or elsewhere".
The 28 ministers endorsed the missile strikes and considered steps to deepen Assad's isolation.