The expulsions were the most ever by the US against Russia, and came in response to a suspected Russian nerve-agent attack on a former spy and his daughter in England. On Monday he said he would decide within 48 hours on a forceful answer to the attack in Syria, later telling reporters: "When, I will not say, because I don't like talking about timing".
She insisted the U.S. had sent "a strong message" about the use of chemical weapons.
"From the point of view of the president, this was aggression and we share this position", Russian lawmaker Sergei Zheleznyak said after his meeting with Assad, according to Russia's TASS news agency. The OPCW did not immediately respond to a request for comment on whether the work would go ahead.
Syria has refused to negotiate an end to the civil war that is now in its seventh year, and it's time for Russian Federation, a Syrian ally, to make that happen, Haley said.
The United States, Britain, and France struck targets in Syria on Friday night to penalize the regime in Damascus for its alleged use of chemical weapons against civilians a week ago.
Nebenzia blamed Friday's joint military strikes, saying they violated global law and undermined the authority of the Security Council.
Haley said the United Nations would continue to work on a diplomatic solution but added that Assad was "not worthy" of direct talks with the U.S. She said the time had come for Russian Federation and Iran to bring peace to the beleaguered nation. "We can not no longer tolerate the trivialization of the use of chemical weapons which presents an immediate danger to the Syrian people and to our collective security".
Ms Haley also made it clear that the United States will not be pulling troops out of Syria right away, saying USA involvement there "is not done".
They also endorsed the US, British and French air strikes carried out on Saturday that Western powers said were a response to an April 7 poison gas attack on the rebel enclave of Douma and were seen as a way to stop the use of chemical weapons. "We warned that such actions will not be left without consequences".
"If you look at what Russian Federation is doing, they continue to be involved with all the wrong actors, whether their involvement in Ukraine, whether you look at how they are supporting Venezuela, whether you look in Syria and their way of propping up Assad and working with Iran, that continues to be a problem", Haley said, adding that the use of a poisoning agent against a spy in England is "another issue". The Kremlin readout said that Putin warned against rushing to blame the Syrian government before conducting a "thorough and objective probe".
"We did not give diplomacy just one chance".
The Russian currency climbed as much as 0.7 percent to 61.637 versus the dollar on Monday after earlier falling as much as 0.9 percent.
"I can not be impolite with the heads of other states but you quoted the leaders of France and the United Kingdom and USA and, frankly speaking, all the evidence they quoted was based on media reports and social media". Hezbollah has hundreds of fighters backing Assad's forces. Syria's civil war, which began as a popular uprising against Assad, is now in its eighth year. Russian Federation has pursued a separate track for political negotiations, hosting talks in Sochi.
On Fox News, Haley also said the United States would not pull its troops out of Syria before three goals have been accomplished: defeating ISIL militants, ensuring chemical weapons will not be used and maintaining the ability to watch Iran.
His choice of words recalled a similar claim associated with President George W. Bush following the US -led invasion of Iraq. Bush addressed sailors aboard a Navy ship in May 2003 alongside a "Mission Accomplished" banner, just weeks before it became apparent that Iraqis had organized an insurgency that tied down US forces for years. The president said Sunday on Twitter that he knew the media would seize on it "but felt it is such a great Military term, it should be brought back".
Later Sunday, Trump sent a letter to congressional leaders informing them in writing of his decision to order the strike.
"The US mission has not changed - the president has been clear that he wants US forces to come home as quickly as possible".
The missiles didn't strike any locations where Russian military forces are based; instead, hitting targets they believe are Syrian government chemical weapons labs. "We are evaluating but nothing to announce right now", she said.
Trump previously has said he wanted United States troops out of Syria quickly, but Haley said there's no timetable for withdrawal. The ministry claimed that the Syrian government kept a stockpile of chemical weapons precursors at the site.