WASHINGTON - US President Donald Trump has ordered the expulsion of 60 Russian diplomats and intelligence officials, and the closure of the Russian Consulate in Seattle in response to the poisoning of a Russian ex-spy in Britain earlier this month.

The Russian officials, including 12 from the Russian mission at the United Nations, were asked to leave the United States within seven days, senior US officials said Monday, speaking on condition of anonymity.

"The United States takes this action with NATO allies and partners around the world in response to Russia's use of military-grade chemical weapon on the soil of the United Kingdom," said the officials.

European Council President Donald Tusk announced Monday in Varna, Bulgaria that 14 member states of the European Union have also decided to expel Russian diplomats.

Sergei Skripal, 66, a former Russian intelligence officer, and his 33-year-old daughter Yulia were found unconscious on a bench at a shopping center in Salisbury on March 4.

They remain in critical condition after exposure to a nerve agent, which, according to the British authorities, could have originated from Russia.

Moscow has denied any involvement in the incident and insisted on participating in direct investigation into the case.

The Russian Foreign Ministry said Monday that Russia "strongly protests" diplomats expulsion by the United States and 14 European countries, vowing to retaliate.

Russia Ambassador to the United States Anatoly Antonov told reporters on Monday that Moscow will give adequate response to the US expulsion decision.

The White House said Monday in a statement that the closure of the Russian Consulate in Seattle was due to its proximity to one of the US submarine bases and Boeing.