A staunch ally of President Bashar al-Assad, Russian leader Vladimir Putin said he regarded the US action as "aggression against a sovereign nation" on a "made-up pretext”.
And he savaged the “cynical attempt” to distract the world from civilian deaths in Iraq, according to spokesman Dmitry Peskov.
Just hours after the strikes, he announced the attacks had seriously damaged ties between Washington and Moscow – which a spokesman claims was already “in tatters”.
Adding the missile strike broke international law, Russia’s foreign ministry also said it was “obvious” that the US strikes had been prepared before the chemical attack.
Putin and Trump have clashed over the controversial missile strike
Two US warships fired 59 cruise missiles from the eastern Mediterranean Sea
Two US warships fired 59 cruise missiles from the eastern Mediterranean Sea at the Syrian airbase today following a poison gas attack in a rebel-held area on Tuesday.
At least 70 people, many of them children, were killed in the chemical attack in the Syrian town of Khan Sheikhoun – but the Syrian government has denied it was behind the atrocity.
Now the US has launched its toughest direct action so far during Syria's six-year-old civil war.
Trump launches military strike against Syria Fri, April 7, 2017
U.S. President Donald Trump launched 59 Tomahawk missiles against Syria in response to its chemical attack on its own civilians
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Trump ordered a massive military strike against a Syria
Washington's step will inflict major damage on US-Russia ties
Putin's spokesman Dmitry Peskov
And the move has left Donald Trump facing his biggest foreign policy crisis since his inauguration, further heightening tension with Russia and Iran.
Announcing the attack, President Trump said: "Years of previous attempts at changing Assad's behaviour have all failed and failed very dramatically.”
US officials said they informed Russian forces ahead of the missile attacks and took great pains to avoid hitting Russian troops at the base.
Syria has been devastated by airstrikes
Two US warships fired 59 cruise missiles at a Syria airbase
But Russian strongman Vladimir Putin has lashed out at the controversial decision – which Trump claims was in America’s “vital national security interest”.
Kremlin and pro-Kremlin lawmakers have since suggested the missile launch had dealt a significant blow to any hopes of doing business with Trump.
Mr Peskov said: ”Putin views the U.S. strikes on Syria as aggression against a sovereign state in violation of the norms of international law and on a made-up up pretext.
"Washington's step will inflict major damage on US-Russia ties.”
US officials said they informed Russian forces ahead of the missile attacks
He added Russia did not believe that Syria possessed chemical weapons and that the move would cause a serious obstacle to creating an international coalition to fight terrorism.
Russia is now expected to call for an urgent meeting of the UN Security Council to discuss the matter.
Iran also denounced the "destructive and dangerous" strike, the Students News Agency ISNA quoted a Foreign Ministry spokesman as saying.
Images show the deadly conflict in Syria Mon, March 13, 2017
Devastating images show the horrifying aftermath from the on-going war in Syria
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Still image shows Russian Bastion coastal missile launchers launching Oniks missiles at unknown location in Syria
The spokesman added: ”Iran strongly condemns any such unilateral strikes … Such measures will strengthen terrorists in Syria … and will complicate the situation in Syria and the region.”
However Britain gave its backing to the military action in the beleaguered region.
A government spokesman said: “The UK government fully supports the U.S. action, which we believe was an appropriate response to the barbaric chemical weapons attack launched by the Syrian regime and is intended to deter further attacks.”