Russia’s ambassador to the United Kingdom warned Wednesday that British Prime Minister Theresa May’s expulsion of Russian diplomats over an alleged assassination attempt is a “provocation.”

“I’ve just had a meeting at the Foreign Office and I told them that everything the British government is doing at the moment is absolutely inadmissible and we’re considering their steps as a provocation,” Alexander Yakovenko, Russia’s top diplomat in the U.K., said according to Russia’s state-run media.