The April 6 US military missile strike that targeted Shayrat airfield in Syria was a measured response to Syrian President Bashar Assad regime's April 4 chemical weapons attack in Khan Sheikhoun, Syria, Defense Secretary Jim Mattis said in a statement issued today.
Deeming it "unclear" whether Russian Federation had been "incompetent" or complicit in the deadly attack, Tillerson said: "This distinction doesn't much matter to the dead".
The United States Secretary of Defense Jim Mattis on Monday said that the U.S. will not allow the Syrian government to use chemical weapons against Syrian civilians again. "I think this president has made it very clear that if those actions were to continue, further action will definitely be considered by the United States".
The United States blamed President Bashar Assad's government and launched almost 60 cruise missiles on Friday at the Shayrat air base in the central province of Homs, where it claims the attack originated.
President Donald Trump, in his biggest foreign policy decision since taking office in January, ordered the strikes after concluding that Syria waged a nerve gas attack in rebel-held territory that killed 87 people, many of them children.
"We want to relieve the suffering of the Syrian people".
"I hope that what the Russian Government concludes is that they have aligned themselves with an unreliable partner in Bashar al-Assad..." U.S. Mattis said there was no doubt that Damascus was responsible.
On Tuesday, US officials laid out the case against Assad over the chemical attack in Syria's Idlib province that prompted Trump to order an air strike with 59 cruise missiles on a Syrian air base last week.
Separately, British Foreign Secretary Boris Johnson said on Monday, ahead of a meeting of G7 Foreign Ministers in Italy, that "it's time for Vladimir Putin to face the truth about the tyrant he is propping up". The Syrian government also denied the allegation, saying its air force bombed a rebel arsenal that had chemical weapons stored inside.
Russian Federation - the main military supporter of Syria's regime - on Tuesday said it was demanding the United Nations conduct an investigation into the chemical attack.
Putin told reporters: "It reminds me of the events in 2003 when U.S. envoys to the Security Council were demonstrating what they said were chemical weapons found in Iraq".
Speaking after Tillerson said earlier on Tuesday he hoped Russian Federation would conclude it was wrong to align itself with the Syrian government, Putin said Moscow would tolerate Western criticism of its role in Syria but hoped that attitudes would eventually soften.