"Did a chemical weapons attack happen?"
"You don't rush decisions like this", Ms Haley said.
"We hope that there will be no point of no return - that the USA and their allies will refrain from military action against a sovereign state", Mr Nebenzia said.
The U.S., France and Britain have been in extensive consultations about launching a military strike as early as the end of this week, U.S. officials have said.
When asked about expectations that the U.S. will launch a punitive strike on Syria over the attack, U.S. Secretary of Defense Jim Mattis said, "Some things are simply inexcusable - beyond the pale - and in the worst interests of not just the chemical weapons convention, but of civilization itself". But Mattis and other members of his national security team cautioned Trump during the meeting that such a strategy could pull the U.S. into direct conflict with Russian Federation and Iran.
It said the attack was a flagrant violation of global rules and regulations and ignores Syria's sovereignty and territorial integrity.
"The immediate priority is to avert the danger of war", said Moscow's United Nations ambassador Vassily Nebenzia on Thursday.
"There is no credible proof of this", Nebenzia said.
The United States is consulting with Britain and France about a joint military response to the attack in Douma that medics and rescuers said left at least 40 people dead on Saturday.
He did not say what the evidence was.
The Pentagon has said the strikes successfully hit the three chemical weapons facilities which were targeted. "We can not take such risks", said Mr Dvorkovich at a forum.More news: Duo pose as police; beat, rob woman
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USA allies have offered strong words of support for Washington but no clear military plans have yet emerged. This scenario, he said, "cannot be tolerated ... especially in light of the deployment in Syria of the Russian contingent".
"After examining the videos and images of victims published online, they (intelligence services) were able to conclude with a high degree of confidence that the vast majority are recent and not fabricated", the report said. "I really, really am". And the Defense Ministry even made sure to note that while Syria shot down some cruise missiles, Damascus did so using its own, Soviet-made - not Russian-made - equipment.
"If it is finished, and there is no second round, it will be considered limited", the official told Reuters. "No other group" could have carried out that attack, May said, adding that the allies' use of force was "right and legal".
Mattis, who USA officials said had earlier warned in internal debates against too large an attack that would risk confrontation with Russian Federation, described the strikes as a "one time shot" to dissuade Assad from "doing this again".
Speaking to reporters in Moscow, Lavrov reiterated a strong warning to the West against military action in Syria. Many of them also reportedly headed north to Aleppo.
The Syrian government has repeatedly denied any use of banned weapons.
Haley kept up the pressure on Russian Federation.
Syrian TV said three civilians were wounded in one of the USA -led strikes on a military base in Homs, although the attack was aborted by derailing the incoming missile.
She noted that In 2017, Moscow "killed" a Joint Investigative Mechanism, which the United Nations established in 2015 to investigate and assign accountability for chemical weapons use in Syria.
On Tuesday, Russia vetoed a resolution that would have set up an investigation into the attacks.
"Today marked a landmark event in Syria's history", said Yuri Yevtushenko, who heads the Russian Center for Reconciliation of the Opposing Parties in Syria.