Britain hailed the mass expulsions as a "turning point" for the West's attitude to a "reckless" Russian Federation, but Moscow denies responsiblity for the poisoning and has vowed to carry out tit-for-tat measures of its own.
In the toughest action that President Donald Trump has taken against Russia since coming to office, the United States has said it will expel 60 Russians, including 12 intelligence officers from Russia's mission to the U.N. headquarters in NY.
Last week, following an European Union summit in Brussels, the U.K., Germany, and France reaffirmed that the Russian state was responsible for the nerve agent poisoning of Skripal and his daughter.
North Atlantic Treaty Organisation has expressed the Allies' support to Britain and called on Russian Federation to address Britain's questions on March 14 and 15.
But Stoltenberg, who said earlier this month he did not want a new Cold War with Moscow, said the alliance planned to continue its "dual-track approach of strong defence and openness to dialogue" with Russian Federation.
He stressed, however, that Tuesday's decision did not change the alliance's overall policy towards Russian Federation.
Former Russian double agent Sergei Skripal and his daughter have been gravely ill since the nerve agent attack earlier this month in Salisbury, England.
They remain in critical condition after exposure to a nerve agent, which, according to the British authorities, could have originated from Russian Federation.
Moscow has fiercely denied any involvement in his attempted murder, instead pointing the finger at London.
This has been done so far by several other European countries that are not members of the EU: Ukraine (13), Norway (one), Albania (two) and Macedonia (one).
Dublin said it will expel one Russian diplomat, while Chisinau announced it had asked three diplomats to leave the country. It also announced to suspend all planned high-level contacts with Russian Federation, and boycott this year's World Cup in Russian Federation by ministers and royal family members. He warned that Moscow will retaliate for the expulsions, saying "such boorishness can't be tolerated".
The Prime Minister added: "It is also important to note that our partners are not only taking these measures out of solidarity with the United Kingdom, but also because they recognise the threat that these Russian networks pose to the security of their own countries and the pattern of Russian aggression which has affected us all".