Britain has already expelled 23 Russian diplomats. Moscow retaliated by sending back the same number of British diplomats and suppressing British cultural institutions in the country.
Croatia: Prime Minister Andrej Plenkovic said Croatia will expel a diplomat
Czech Republic: The Czech Republic will expel three diplomats, Prime Minister Andrej Babis and Foreign Minister Martin Stropnicky have announced a press conference. The Czech Foreign Ministry tweeted that it had declared the diplomats "personae non gratae".
Estonia: The Estonian Foreign Ministry informed CNN that a Russian diplomat, a Russian defense attaché, is being expelled.
Finland: Finland will expel a diplomat, the Foreign Ministry said.
France: French Foreign Minister Jean-Yves Le Drian has announced the expulsion of four diplomats who must leave the country within a week. He said that the decision followed the conclusions of the European Council that the attack "posed a serious threat to our collective security" and that France "acted in solidarity with our British partners".
Germany: The German Foreign Ministry said Monday it would expel four diplomats. "In close coordination within the European Union and with NATO allies, the federal government has decided to ask four Russian diplomats to leave Germany within seven days, and the request was sent to the Russian Embassy today," the ministry said in a statement.  Hungary: The Ministry of Foreign Affairs said Hungary would expel a diplomat over "what was discussed at the European Council," adding that the diplomat "also conducts intelligence activities"
Italy: The Italian The State Department says it will identify two Russian diplomats from the embassy in Rome "as a sign of solidarity with the United Kingdom and in coordination with European partners and NATO."
Latvia: The Foreign Ministry informed CNN that it would identify a diplomat and a private citizen who runs the office of a Russian company in the capital, Riga.
Lithuania: Foreign Minister Linas Linkevicius said on Twitter that the country would expel three diplomats "in solidarity with Britain via #SalisburyAttack". Lithuania would sanction an additional 21 people and ban 23 others from entry.
Poland: The Polish Foreign Ministry said it would drive out four diplomats and said the attack showed "that a similar immediate threat to the territory and the citizens of the EU and the NATO countries can occur everywhere . "
Romania's Foreign Ministry said on Twitter that a diplomat would be expelled.
Sweden: The Foreign Ministry informed CNN that it would expel a diplomat.
Albania: The Foreign Ministry informed CNN that it would expel two Russian diplomats. In a statement, the ministry called each diplomat a "persona non grata" and said that the couple's activities "did not correspond to their diplomatic status".
Canada: Ottawa said it expelled four Russian diplomats who allegedly were intelligence officers "or individuals who used their diplomatic status to undermine Canadian security or interfere in our democracy." In addition, it rejected three requests from Moscow for additional diplomatic staff. "The attack with nerve agent poses a clear threat to the rules-based international order and the rules created by the international community to ensure that chemical weapons will never again destroy human lives," said Secretary of State Chrystia Freeland.
Norway: The Foreign Ministry informed CNN that it would drive out a Russian diplomat in response to the attack. "The use of a nerve agent in Salisbury is a very serious matter," Norwegian Foreign Minister Ine Eriksen Soreide said in a statement. "Such an incident must have consequences."
United States: The White House said it drove out 60 Russian diplomats identified as intelligence agents and also announced the closure of the Seattle Russian Consulate. It is the strongest action Trump has ever taken against Russia so far. Of those who are expelled, 48 of the alleged intelligence agents work at the Russian Embassy in Washington and 12 at the United Nations in New York, senior government officials said.