According to reporting by Reuters, the US will be expelling 60 Russian diplomats while the European Union is set to expel 100 diplomats following the nerve attack on a former Russian double agent, which Moscow is being held responsible for.

Key quotes (Reuters source):

"It was the strongest action that U.S. President Donald Trump had taken against Russia since coming to office. He has been criticized by Democrats and members of his own Republican Party for failing to be tough enough on Russia over U.S. allegations of Russian meddling in the U.S. electoral system."

"British Foreign Secretary Boris Johnson said on Twitter Monday’s “extraordinary international response by our allies stands in history as the largest collective expulsion of Russian intelligence officers ever and will help defend our shared security”. May said the coordinated measures sent the “strongest signal to Russia that it cannot continue to flout international law”. Britain had evidence Russia has investigated ways of distributing nerve agents for assassinations, May told parliament."

"Russian U.N. ambassador Vassily Nebenzia called it “a very unfortunate, very unfriendly move”. Trump also ordered the closure of the Russian consulate in Seattle because of its proximity to a U.S. submarine base and planemaker and defence contractor Boeing Co, a senior U.S. official said. Seattle was a hub of Russian cyber espionage, both political and commercial, according to two U.S. intelligence officials."