US Ambassador to the United Nations has accused Russia of carrying out the recent nerve agent attack against a former spy in the UK, calling for action against Moscow to ensure it never uses “chemical weapons” again.

Speaking at the UN Security Council on Wednesday, Haley said the US agreed with the British government’s assessment that Russian agents had used deadly chemicals in an attempt to kill 66-year-old Sergei Skripal and his daughter Yulia in Salisbury last week.

"If we don't take immediate concrete measures to address this now, Salisbury will not be the last place we see chemical weapons used," Haley argued. "They could be used here in New York or in cities of any country that sits on this council."

Haley also defended London’s move earlier in the day in expelling 23 Russian diplomats over the row, saying Washington stood in "absolute solidarity" with London.

British Prime Minister Theresa May told the House of Commons in Parliament on Wednesday that Russia had expressed "disdain" for Britain's wish for an explanation into the matter.

The US envoy claimed that the nerve agent was “military-grade” and explained Russia’s support for the government of Syrian President Bashar al-Assad, whom Washington and its allies accuse of using chemical weapons against Syrian people.

"Time and time again, members states say they oppose the use of chemical weapons under any circumstance," said Haley. "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."

Haley’s stance echoed those of Rex Tillerson, the ousted secretary of state who this week called the alleged nerve agent attack "a really egregious act" that appears to have "clearly" come from Russia.

The remarks by the two administration officials exceeded what the White House had offered.

White House press secretary Sarah Sanders said earlier that the attack was "reckless, indiscriminate and irresponsible" but did not go as far as openly pinning the blame on the Kremlin.

Russia has denied all allegations, asking the UK and the US to back up their claims by providing evidence.

"We demand that material proof be provided of the allegedly found Russian trace in this high resonance event. Without this, stating that there is incontrovertible truth is not something that we can take into account," Russian UN envoy Vassily Nebenzia said Wednesday.