But after the attack, Russia's Ministry of Defence quickly said no Russian air defences were deployed against the incoming fire, even though thousands of the country's troops are stationed across Syria.
The western strikes on Syria are "unacceptable and lawless", according to Russia's Foreign Affairs Minister, Sergey Lavrov.
Putin said the actions violated the U.N. Charter and if they continue, "it will inevitably entail chaos in worldwide relations", the statement said.
The Trump administration on Monday will announce new sanctions on Russian Federation over the Syrian use of chemical weapons, United Nations Ambassador Nikki Haley said Sunday.
The Western countries blame Assad for the Douma attack that killed dozens of people. Russian Federation is, of course, an ally of Syria. Russian Federation is a key ally of Assad and has been waging an air campaign in support of his forces since 2015.
French president Emmanuel Macron has clarified comments that he "convinced" his USA counterpart Donald Trump to maintain a USA military presence in Syria - a remark which prompted a rebuttal from the White House.
According to a statement from the UK Ministry of Defense, the RAF fighters were targeting "a military facility - a former missile base - some fifteen miles west of Homs, where the regime is assessed to keep chemical weapon precursors stockpiled in breach of Syria's obligations under the Chemical Weapons Convention".
"The US mission has not changed - the president has been clear that he wants US forces to come home as quickly as possible", White House spokeswoman Sarah Sanders said. "The US will be a partner and a friend".
The sanctions were announced Sunday by Nikki R. Haley, the US ambassador to the United Nations and the administration's leading public voice excoriating Russian Federation in recent days.
"This action gives a strong signal to extremists and militants that they are doing right things", Zakharova is quoted as saying.
It seeks answers from Syria on gaps in its chemical weapons declaration to the Organization for the Prohibition of Chemical Weapons.
The inspectors were due to attempt to visit the Douma site.
Mekdad declined to comment to reporters waiting outside the hotel where the meeting took place.
It is noted that according to the officials of the security sector, the British government communications Centre (GCHQ, the intelligence Agency responsible for protecting the public value and electronic intelligence - ed.) will "continue to expose the unacceptable behaviour of Russian Federation in cyberspace".
Syrian air defenses responded to the joint strikes by the US, France and Britain.
The decision to strike, after days of deliberations, marked Trump's second order to attack Syria; he authorized a barrage of Tomahawk cruise missiles to hit a single Syrian airfield in April past year in retaliation for al-Assad's use of sarin gas against civilians.
The strikes against Syria in retaliation for a suspected chemical attack that killed dozens in the Damascus suburb of Douma were created to avoid provoking Russian Federation into a response. Its fact-finding team reached Syria on Saturday, the day of the US-led airstrikes against Syrian government targets in response to the April 7 attack.
Yuri Shvytkin, a deputy chairman of the State Duma Defense Committee, said that the strikes on Syria are an ill-thought and provocative step that can lead to unpredictable consequences.
The UK government blamed Russia for the poisoning, and the episode prompted the expulsions of Russian diplomats from more than 20 countries. That had led to feverish speculation on Russian television, and from some Russian politicians, that a USA strike on Syria could quickly devolve into a nuclear standoff as risky as the Cuban missile crisis.
Syrian state TV said the attacks were a "blatant violation of worldwide law and shows contempt for global legitimacy".
The British envoy to the OPCW said the body had recorded 390 allegations of the use of banned chemicals in Syria since 2014, and that a failure by the OPCW to act risked allowing "further barbaric use of chemical weapons".
"As expected, the main objective was a show of force", Lukyanov told state news agency TASS, referring to the strikes carried out jointly by the US, Britain and France.