Nikki Haley, the US ambassador to the United Nations, has demanded the body’s security council hold Russia to account in the Trump administration’s strongest statement yet on the Salisbury attack.

She warned that a similar poisoning could be repeated in New York or other global cities in the future if the UN failed to take action.

Ms Haley said that Russia “is responsible” for the attack and warned of an "alarming" wider pattern of "dangerous and destabilising activity" from the country.

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

“This is a defining moment. Time and time again member states say they oppose the use of chemical weapons under any circumstances.

“Now one member stands accused of using chemical weapon on the sovereign soil of another. The credibility of this council will not survive if we fail to hold Russia to account.”

Ms Haley directly blamed Russia, saying: "The United States believes that Russia is responsible for the attack on two people in the United Kingdom, using a military-grade nerve agent."

Speaking at an emergency council meeting, Ms Haley mentioned the killing of North Korean leader Kim Jong-un’s brother with a nerve agent and the use of chemical weapons in Syria as she listed incidents similar to Salisbury.

She said that America stood in “absolute solidarity” with Britain and called on Russia to provide answers to the questions posed by the UK government.

Ms Haley said of the Salisbury poisoning: "This was a reckless and indiscriminate act that put at risk the lives of civilians."

In remains unclear exactly what action Ms Haley is seeking from the UN security council, which includes Russia as one of its permanent members.