It was the latest sharp split between the United States and Russian Federation over the incident, which has deepened antagonism between the two countries in the wake of the attack.
He said: "I'm amazed that this was the conclusion". I think he wants to help us with North Korea, we talked trade, we talked a lot of things, and I said the way you're going to make a good trade deal is to help us with North Korea, ' Trump said.
"They have chosen to side with a murderous, barbaric criminal, rather than with their worldwide peers".
The foreign secretary urged the country to stop acting "as a lifeline for Assad's murderous regime".
UN Syria mediator Staffan de Mistura warned the UNSC on Wednesday that fragile progress in peace talks was now "in grave danger".
Secretary of State Rex Tillerson made it clear on Wednesday that the United States will not support the continued rule of Syrian President Bashar al-Assad.
Following the April 4 attacks, Haley asserted that there could be no political change in Syria while Assad remained in power.
Secretary of State Rex Tillerson said that current U.S. -Russia relations are at a "low point". "No one showed us anything, no one said anything, although we repeatedly asked to produce the details on which these unfounded accusations lie".
"The longer-term status of President Assad will be decided by the Syrian people", Tillerson had said, when asked whether the US would get involved in Syria's internal politics on March 30. "The world's two foremost nuclear powers can not have this kind of relationship", Tillerson said.More news: Stock with Unusual Volume: Noble Energy, Inc. (NBL)
But the two nations remain at odds over US airstrikes on Syria - following last week's chemical attack on Syrian civilians.
Trump's spokesman Sean Spicer said Tillerson would go into the meeting with Lavrov to "make sure we let Russian Federation know that they need to live up to the obligations it has made" to halt Assad's chemical weapons use. And he suggested that possible war crimes charges could be levied against the Syrian leader.
The US now assesses that Syria has re-established a unit of personnel associated with chemical weapons that existed before the 2013 agreement in which the Syrian government pledged to give up its weapons inventory.
At the start of his meeting with Lavrov, Tillerson said he wanted to "clarify areas of common objectives, areas of common interest - even where our tactical approaches may be different - and further clarify areas of sharp difference".
He said the visit - the first to Moscow by a senior Trump administration official - offered an opportunity to clarify the chances of cooperation "above all on the formation of a broad anti-terrorist front".
Moscow last week suspended its memorandum with the Washington after its missile attack on Syrian military air base.
But Moscow refuses to bow to worldwide pressure with Mr Putin to deny the Syrian government was to blame for the gas attack and adding a new theory that the attack may have been faked by President Assad's enemies.
"Right now we're not getting along with Russian Federation at all", Trump said flatly during a White House news conference.
"It's really pitiful to hear such irresponsible and provocative statements from the most important leader in the Western world", Ja'afari said. "I do not know who saw them".