The prime target of the operation was the Barza Research and Development Centre in the greater Damascus area, which McKenzie noted was "one of the most heavily defended aerospace areas in the world". He also said Congress must play an oversight role in such military actions. A spirited debate is expected.
US officials said Saturday that they believed the strikes would prevent future chemical attacks by the Syrian regime, but warned that the USA was prepared to "sustain" its operation if Assad continues his aggressions.
"This collective action sends a clear message that the worldwide community will not stand by and tolerate the use of chemical weapons", she said.
Russian President Vladimir Putin on Saturday reaffirmed Russia's view that the purported chemical attack was a fake, criticizing the US and its allies for launching the strike without waiting for inspectors from the Organization for the Prohibition of Chemical Weapons, the worldwide watchdog group, to visit the area.
"The people martyred by chemicals is a certain amount, but the people martyred by conventional weapons is much, much more", he said.
Russian Ambassador Vassily Nebenzia accused the West of "hooliganism" and demanded that it "immediately end its actions against Syria and refrain from them in the future". Moscow stated that the attack had been carried out initially on the eve of the arrival of OPCW experts to the Syrian capital who aimed to probe the alleged Douma chemical attack. Some of those more than 40 Syrian missile interceptors, he suggested, might have hit civilian targets.
Barrel bombs are large containers that are packed with fuel, explosives and scraps of metal. The use of which, she says, "is inexcusable" and "illegal".
When asked whether the us should expect retaliation from Syrian or Russian forces for the attack, McKenzie stressed that military forces are preparing for the possibility.
The assessment cites "the absence to date of chemical samples analyzed by our own laboratories". "Instead of weakening the government, it only made it stronger", he said by telephone from Damascus.
"A combined operation with the armed forces of France and the United Kingdom is now under way". Syria denies responsibility and says it gave up its chemical arsenal. She urged Russian Federation and Iran to help prevent any further use of chemical weapons by Assad's regime.
Disputing the Russian military's contention that Syrian air defense units downed 71 allied missiles, McKenzie said no USA or allies missiles were stopped.
The missiles hit their targets within a minute or two of each other, McKenzie said, striking around 4:00 am Syrian time (0100 GMT). "Over the last 18 months, Russian Federation has completely recovered the Syrian air defense systems, and continues its development".
United States Ambassador to the United Nations Nikki Haley speaks to members of the United Nations Security Council during an emergency meeting on Syria at the U.N. headquarters in NY, U.S., April 14, 2018.
Mr Putin added that the strike had a "destructive influence on the entire system of global relations".
US forces launched targeted missile strikes on Friday at key military outposts in Syria, where the government is thought to have stored chemical weapons used in a strike that killed over 40 civilians last weekend.
McKenzie's remarks contradict an earlier assessment by Russian Federation, a key Syrian ally.
The three sites targeted were "fundamental components" to Syria's chemical weapons program, according to Marine Lt. Gen. Kenneth McKenzie.
The attack "was a victory for Syria", former lawmaker Sharif Shehadeh said by phone from Damascus. Despite deep divisions in America, the US government can still rally allies to do what's right.