"We will work calmly, methodically and professionally, using all opportunities to remove the situation from its current extremely risky political peak".
The Syrian civil war is not in its seventh year.
The inspectors were due to attempt to visit the site of the suspected gas attack in Douma on April 7, which medical relief organisations say killed dozens of people. Moscow condemned the Western states for refusing to wait for OPCW's findings before attacking.
Russian leader Vladimir Putin reaffirmed the Kremlin's skepticism about the allies' Douma claim, saying Russian military experts had found no trace of the attack.
Assad didn't comment on calls by the US State Department to declare alleged Syrian stockpiles of chemical weapons during the meeting. "We know that it is now up to Bashar al-Assad on whether he's going to use chemical weapons again".
In a separate interview, Haley told CBS News that new sanctions against Russian Federation, which has forces in Syria supporting the Assad regime, would be announced Monday that would "go directly to any sort of companies that were dealing with equipment related to Assad and chemical weapons use".
The U.S. has vowed to also squeeze Syria's allies Russian Federation and Iran.
Haley rejected the premise posed by Fox News anchor Chris Wallace that the US has condoned Assad's use of conventional weapons to kill rebels attacking his forces, just not chemical agents.More news: Sunday's ACM Awards: What to Expect and Who You'll See
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Trump has made clear he wants to withdraw the roughly 2000 USA troops involved in the anti-Islamic State campaign in Syria. "And they will go directly to any sort of companies that were dealing with equipment related to Assad and chemical weapons use".
She also said she's not impressed with the reaction of Prime Minister Justin Trudeau, who expressed support for the strikes but seems reluctant to get directly involved. "The humanitarian intervention is a legally debatable concept at the present time", he said in a TV interview with the BBC.
Syria released video of the wreckage of a bombed-out research lab, but also of Assad arriving at work as usual, with the caption "morning of resilience" and there were no immediate reports of casualties.
President Donald Trump on Sunday defended his use of the term "mission accomplished" to describe the Friday night attacks on Syria, even as President George W. Bush's former spokesperson said he wouldn't have recommended the president use the term. Let the other people take care of it now [.] We're going to have 100 percent of the caliphate, as they call it, sometimes referred to as land. The U.S. and its allies accused Assad's forces of using chemical weapons, a claim Syria and Russian Federation have rejected.
"This was very strong attack on the chemical weapons program".
French Foreign Minister Jean-Yves Le Drian said in an interview in Sunday's Journal Du Dimanche newspaper that "we should join our efforts to promote a political process in Syria that would allow a way out of the crisis".
US Senate Democratic leader Chuck Schumer warned of the risks of being drawn into "a greater and more involved war in Syria".