Nato chief Jens Stoltenberg says the alliance will expel seven staff from the Russian mission.
A top Russian diplomat has said Moscow is preparing a "tough response" to today's announcement by the United States that it is expelling 60 Russian diplomats.
The United States, the European Union nations and some other countries, including Ireland, have announced they would expel a total of more than 130 Russian diplomats in response to the nerve agent attack on a former Russian intelligence officer and his daughter in Britain.
Sergei Skripal and his daughter Yulia remain in critical condition in the hospital in Salisbury after being exposed to what British authorities say was a Soviet-made military-grade nerve agent on March 4th.
Russian Deputy Foreign Minister Sergei Ryabkov told the RIA Novosti news agency that Moscow was disappointed by the US announcement that it would expel 60 Russian diplomats and shut down a consulate in Seattle.
Mr Ryabkov said the US move "will be met with a tough response", but he did not elaborate.