"The U.S. - the possessor of the biggest arsenal of chemical weapons - has no moral right to blame other countries".
In a televised address announcing the action, Trump said he had chose to take action because last weekend's action by Assad "was a significant attack against his own people", and "not the actions of a man, they are crimes of a monster instead".
Targets included a "scientific research center" located in the Damascus area and a chemical weapons storage facility west of Homs, Dunford confirmed.
"We are prepared to sustain this pressure, if the Syrian regime is foolish enough to test our will", she said.
"The objective of our actions tonight is to establish a strong deterrent against the production, spread and use of chemical weapons", Trump said.
Russian Federation has always been an ally of Syrian President Bashar al-Assad.
He said the analysis was done at the request of the Organization for the Prohibition of Chemical Weapons.
Russian officials had said before the suspected gas attack in Douma that rebels in the eastern Ghouta suburbs of Damascus were plotting chemical attacks to blame the Syrian government and set the stage for a USA strike.
Arab League should try to solve regional problems instead of blaming Iran
There was little mention of Syria, whose president Bashar al Assad was not invited to the summit. The summit begins on Sunday in the East coast city of Dammam .
Turkey, an important player in the Syrian conflict, said it viewed the airstrikes as "an appropriate response" to the Douma attack.
As fears of a Russia confrontation with Western powers mount, French President Emmanuel Macron expressed his "deep concerns" over the situation in Syria in a phone call with Russian President Vladimir Putin. Moscow alleged soon after the suspected April 7 attack that the images of the victims in Douma were fakes.
A spokesman for Russia's defence ministry accused the United Kingdom of being involved in staging the attack.
Russian Federation and Syria also clashed with the three Western allies over the legality of the airstrikes and responsibility for the Security Council's paralysis.
The Russian measure would have condemned the "aggression" against Syria and demanded that the three allies refrain from any further strike.
Russian Federation has countered that the US-led action was aimed at overthrowing Assad and keeping Moscow's influence in check.
But the pinpoint strike did not deter Assad and USA officials, speaking on condition of anonymity, have since investigated as many as 10 suspected chemical attacks.
Nebenzia responded saying the environment is "not very conducive for any rapprochement" and "the political and unsafe military situation we are in now" must be sorted out first.