Ex-spy poisoning: US holds Russia responsible

US Ambassador to the United Nations Nikki Haley on Wednesday slammed Russia over the poison attack that left a former Russian double agent and his daughter comatose on a park bench last week.

"The United States believes that Russia is responsible for the attack on two people in the United Kingdom using a military-grade nerve agent," CNN reported, quoting Haley, as saying.

"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 added,"They could be used here in New York or in cities of any country that sits on this council."

Haley made her remarks at a UN Security Council emergency session.

Earlier on Tuesday, United States President Donald Trump backed the British Government's theory which holds Russia responsible for the poison attack on the former Russian double agent.

"It sounds to me like it would be Russia, based on all the evidence they have. It sounds to me like they believe it was Russia and I would certainly take that finding as fact," Trump told reporters outside the White House.

British Prime Minister Theresa May on Monday stated that it was "highly likely" Russia was to blame for the attack.

In a strongly worded statement to the House of Commons, May said the "military grade" nerve agent used in the attack had been identified as Novichok, a substance developed in the Soviet Union in the 1970s.

Dismissing May's comments Russian Foreign Ministry spokeswoman Maria Zakharova, told CNN, "This is a circus show in the British Parliament. The conclusion is obvious."

Furthermore, Russia has dismissed the accusations as "fairy tales" and denied any involvement in the attack against Sergei Skripal and his daughter Yulia, according to the report.

Retired military intelligence officer Skripal, 66, and his daughter, Yulia, 33, were found slumped on a bench in Salisbury city centre on March 4.