Speaking to reporters in Moscow, Lavrov reiterated a strong warning to the West against military action in Syria, saying any such "adventures" in Syria would increase flows of refugees into Europe.
"Cabinet agreed that the Assad regime has a track record of the use of chemical weapons and it is highly likely that the regime is responsible for Saturday's attack", it said. More than 1,000 people have been killed in eastern Ghouta in the past two weeks, according to Doctors Without Borders.
The White House press secretary, Sarah Huckabee Sanders, said in a brief statement after Trump met with Mattis and other members of his National Security Council: "No final decision has been made".
The French president, Emmanuel Macron, confirmed that France was involved in the air strikes, saying the French role would be limited to Syria's chemical weapons facilities.
While inspectors with the Organization for the Prevention of Chemical Weapons collect soil, biomedical and other environmental samples to determine whether chemicals were used in the attack, the organization will not decide who is responsible.
After years of Syrian civil war, Russian Federation is suddenly terribly concerned that US provocation could lead to war.
"Our strategy remains the same as a year ago", he said.
The strikes appear to signal Trump's willingness to draw the United States more deeply into the Syrian conflict. In another tweet on Thursday, Trump wrote that an attack on Syria "could be very soon or not so soon at all!" "Could be very soon or not so soon at all", Trump said in an early morning tweet on Thursday.
In recent days the administration had weighed how to intensify the attack without collapsing the Assad regime or drawing Russian Federation or Iran further into the fight.
The allied operation comes a year after the US missile strike that Trump said was meant to deter Assad from further use of chemical weapons.
May said she had authorised British armed forces "to conduct coordinated and targeted strikes to degrade the Syrian regime's chemical weapons capability".
"We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents", Trump said.
The strikes are in response to a suspected gas attack on the rebel-held city of Douma last weekend.
Assad said any Western action "will contribute nothing but an increase in instability in the region, threatening global peace and security", Syrian state TV reported. Initial reports indicated the use of chlorine gas, possibly in addition to the nerve agent Sarin. Officials said Thursday the trio has yet to reach firm agreement on the scale or timing of a response. The ministry also pointed at previous use of chemicals by the rebels in fighting with Syrian government troops.
Meanwhile, Labour leader Jeremy Corbyn has accused the Government of "waiting for instructions" from the U.S. and that military intervention risks "escalating an already devastating conflict". Defense Secretary James Mattis told reporters at the Pentagon that the USA was confident that chlorine was used, but couldn't "rule-out" that the deadly nerve agent sarin was launched.
Mrs May and President Trump spoke hours after this meeting and reiterated the use of chemical weapons should not be tolerated. "We hope there will be no point of no return", the envoy said.
Russian Federation has hit back at the United States following a massive air strike on targets in Syria, warning there will be consequences. More broadly, he doubted the wisdom of bombing.
USA military leaders stressed on Friday that the new operation was much broader in scope and was "a one-time shot" aimed at debilitating Assad's chemical weapon program in the long run. "We need to know where that's going, what the objective of it is before we take that act".
But Russia's Defence Ministry said the majority of missiles fired were intercepted by Syrian government air defence systems.
Vassily Nebenzia, Moscow's ambassador to the United Nations, said he "cannot exclude" war between the United States and Russian Federation and urged Washington and its allies to refrain from military action against Syria.
While Trump announced the "precision strikes" in Syria, Trudeau has ruled out any Canadian participation.
US officials have told CBS News the blood samples provided by hospital workers in Syria do indeed confirm the presence of chemicals, but they need to be sure the evidence hasn't been doctored.
Mattis described the strikes as a one-off to dissuade Assad from "doing this again".