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 Hours after British Prime Minister Theresa May announced the UK will expel 23 Russian diplomats as punishment over the nerve agent attack against a former spy on British soil, President Donald Trump has yet to weigh in. "This will be the single biggest expulsion for over thirty years and it reflects the fact that this is not the first time that the Russian State has acted against our country," May said. May announced Monday that it was "highly likely" the Russian government ordered an assassination attempt against Sergei Skripal, a former Russian military intelligence officer who later became a double agent for the UK, in Salisbury, England earlier this month. The United Kingdom believes Russia was behind the attempted murders of Sergei Skripal and his daughter Yulia because the nerve agent used, Novichok , was developed in the Soviet Union and could not be replicated by non-state actors. Haley's remarks echoed those of Rex Tillerson, the ousted secretary of state who this week called the nerve agent attack "a really egregious act" that appears to have "clearly" come from Russia. While answering questions about Tillerson's firing, Trump said of the chemical attack on Skripal, "As soon as we get the facts straight, if we agree with them, we will condemn Russia or whoever it may be." On Wednesday, after May announced the expulsion of the 23 Russian diplomats — the largest number ejected by the UK since the Cold War —multiple US officials, including the US ambassador to the UN and White House staff, said the US stands in solidarity with the UK.  (CNN) US Ambassador to the United Nations Nikki Haley said Wednesday the Trump administration "stands in absolute solidarity with Great Britain" following a nerve agent attack against a Russian double agent and his daughter in the English city of Salisbury last week. Richard Kauzlarich, the former deputy assistant secretary of state in the Bureau of European Affairs, said the White House should have backed the British from the beginning. Related: U.K. to expel 23 diplomats in retaliation for spy poisoning 
 
 She called on the U.N. to take action action, saying that the "credibility of this Council will not survive if we fail to hold Russia accountable." "This latest action by Russia fits into a pattern of behavior in which Russia disregards the international rules-based order, undermines the sovereignty and security of countries worldwide, and attempts to subvert and discredit Western democratic institutions and processes."
– Nikki Haley came out strong against Russia and in support of the United Kingdom on Wednesday following the nerve agent attack that left a former Russian spy and his adult daughter in critical condition in England, CNN reports. "The United States believes that Russia is responsible for the attack," the US ambassador to the UN told the Security Council, adding the White House "stands in absolute solidarity with Great Britain." "Time and time again, member states say they oppose the use of chemical weapons under any circumstance," Haley said. "Now one member stands accused of using chemical weapons on the sovereign soil of another member. The credibility of this council will not survive if we fail to hold Russia accountable." It was by far the most forceful statement out of the Trump administration. Rex Tillerson had said Russia was "clearly" responsible for the attack on Sergei Skripal and daughter Yulia but was shortly fired by Trump, NBC News reports. When asked about Tillerson's firing Tuesday, Trump said "as soon as we get the facts straight" the US would "condemn Russia or whoever it may be." According to Business Insider, former US diplomats have expressed confusion about why the White House hasn't done more to back its ally Great Britain, which has expelled 23 Russian diplomats. Nicholas Burns calls it "judgment day" for Trump. "Will he support Britain unequivocally on the nerve agent attack?" the former US ambassador to NATO says. "Back NATO sanctions? Finally criticize Putin? Act like a leader of the West?"