The strike, meant to show Western resolve in the face of what Trump called persistent violations of global law by Assad, was larger than last year's, when the United States fired 58 cruise missiles at Syria in retaliation for a purported chemical weapons attack by government forces on a rebel-held town in the north of the country.
"More than 100 cruise missiles and air-to-land missiles were fired by the US, Britain and France from the sea and air at Syrian military and civilian targets", the ministry said in a statement quoted by RIA Novosti news agency. Trump said the attack would be sustained to ensure that Syria does not use chemical weapons to attack civilians.
Russia's foreign ministry said Syria had been attacked just as it had a chance for peace.
Syrian state media said air defences were activated to block the attack and published images of smoke clouds hanging over the capital.
Rep. Justin Amash, a Michigan Republican, said: "These offensive strikes against Syria are unconstitutional, illegal, and reckless". He declared on Twitter Wednesday that U.S. missiles "will be coming, nice and new and 'smart!' " And he insisted privately he be able to make good on his promise, even as he sought to obscure his plans in public, the officials familiar with the deliberations said.
Washington, Paris and London have nevertheless insisted that their own secret intelligence points to Mr Assad's guilt, and on Friday, a USA spokeswoman said they had "proof".
Interviewed earlier in the week, Fehmi Khairullah of Hawthorne, who is not related to the mayor, said he did not believe Trump would take strong action against Assad, predicting it would be "another air show or missile show".
The air strikes, however, risk dragging the United States further into Syria's civil war, particularly if Russia, Iran and Assad opt to retaliate.
Col. Gen. Sergei Rudskoi of the Russian military's General Staff said the strikes have not caused any casualties and Syrian military facilities targeted by the U.S., Britain and France have suffered only minor damage, the Associated Press reported.
Mattis says if Assad uses chemical weapons again, there could be more strikes.
Trump's deliberations this week over how to respond to the deadly chemical attack occurred at a tenuous moment for his presidency, with the special counsel's investigation winding its way further into the President's inner circle and many of Trump's trusted aides rushing for the exits.
Mr Dunford said Russia's forces in Syria had been warned through existing "deconfliction" channels that Western planes would be in Syrian air space, but Washington had not revealed the target sites or timing in advance. The Russian embassy has even stated the Putin's insult in unacceptable.
"These are not the actions of a man; they are crimes of a monster instead", Trump said in an address to the nation.
Russia's ambassador to Lebanon on Tuesday had told Lebanon's Al Manar TV that any USA missiles fired at Syria would be shot down and the launch sites targeted, Reuters reported. Dunford said "normal deconfliction channel was used to deconflict airspace" with Moscow, but that the United States did not share with Russian Federation what sites would be targeted.
But as the conflict got more complex - Russian Federation launched its air campaign in Syria in September 2015 and Turkey a few days before - the US found itself increasingly caught up in frictions with other regional players, and at times acted against threats or the repeated use of chemical weapons against civilians.
The statement said that "a significant body of information" pointed to the use of chlorine in the Douma attack while "some additional information" indicated that the nerve agent sarin was also used.
"The Trump administration admitted that it's a one-off attack".
Cristol, however, said the chances of a military escalation remained low.