Nato's boss Jens Stoltenberg said it would expel seven Russian diplomats, and would deny accreditation to another three as part of the push for the worldwide community to punish Putin for the spy poisoning.
"This will send a clear message to Russian Federation that there are costs and consequences for their unacceptable pattern of behavior", he added.
A number of countries including the United States said the Russian diplomats they were throwing out were actually undeclared spies.
Poland and the three Baltic states seem poised to expel Russian diplomats over the poisoning of an ex-Russian spy in Britain earlier this month, based on Russian news reports and diplomatic sources on Monday.
North Atlantic Treaty Organisation has warned that the nerve agent attack on Sergei Skripal and his daughter must have "consequences" and Stoltenberg will hold a news conference in Brussels at 3:30 pm (1330 GMT) to make an announcement on "further decisions", the alliance said in a brief statement.
On March 26, more than 20 countries announced their intention to expel Russian diplomats in solidarity with Britain because of the poisoning of former Russian spy Sergei Skripal in Salisbury.
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And Moldova, the ex-Soviet nation whose pro-Western government is seeking closer ties with the West, on Tuesday also ordered three Russian diplomats to leave within seven days.
Moscow has fiercely denied any involvement in his attempted murder, instead pointing the finger at London.
On Monday, European Council President Donald Tusk announced in Varna, Bulgaria, that 14 European Union (EU) member states had made a decision to expel Russian diplomats in response to the poisoning of a former Russian spy and his daughter in Britain.
"I welcome the worldwide support that we have garnered", she said.
Asked on Monday about a report that the USA would also expel Russian diplomats, presidential spokesperson Dmitry Peskov said that Russia will act according to the principle of reciprocity.
"This is the result of colossal pressure, colossal blackmail which is the main instrument of Washington on the worldwide arena", Russian Foreign Minister Sergey Lavrov said Tuesday.
It responded to Britain's expulsions with its own, and the closure of the British Council cultural organisation - and on Tuesday promised it would hit back against the coordinated moves.