Russia announced on Friday that it had decided to expel six British diplomats from the country, accusing them of engaging in espionage and sabotage work, in a move that highlighted the deepening tensions between Moscow and London.
The Russian Federal Security Service, or F.SB., said that the decision had been made in response to “the numerous unfriendly steps taken by London,” an apparent reference to signals from Britain that it is eager to allow Ukraine to use its “Storm Shadow” long-range missiles against military targets deep inside Russia.
Speaking on Thursday about that potential shift on the use of missiles, President Vladimir V. Putin warned that such a decision would mean that NATO countries were “at war with Russia” and that it would “clearly change the very essence, the very nature of the conflict.”
On Friday, the Kremlin’s spokesman, Dmitri S. Peskov, told reporters that Mr. Putin’s statement was “very important” and that the Russian government had “no doubt” that the message “had reached its addressees.”
The British Foreign Office — which said the accusations of spying by the diplomats were baseless — said that the six had left Russia last month, after Moscow’s notification to London about its decision in early August.
That came after Britain said in May that it was expelling a Russian defense attaché as an undeclared military intelligence officer and that it was imposing other restrictions on the Russian Embassy in London.
At the time, Moscow responded by ordering the British defense attaché to leave Russia. The tit-for-tat exchanges have come amid the backdrop of the war in Ukraine, and the timing of the latest Russian announcement coincided with Prime Minister Keir Starmer’s trip to Washington on Friday.
The proposed use of Britain’s “Storm Shadow” missiles — which would allow the Ukrainian military to strike in Russian territory far from the border — is high on Mr. Starmer’s agenda for the meeting. Britain wants explicit permission from President Biden in order to demonstrate a coordinated strategy with the United States and France, which has virtually the same model of missile.
The F.S.B., the main successor agency to the Soviet-era K.G.B., said that the six expelled diplomats had been sent to Russia by the British foreign service directorate responsible for Eastern Europe and Central Asia.
Since the invasion of Ukraine, the agency’s statement said, the British directorate has turned into “a special service, whose main task is to inflict strategic defeat” on Russia.
The F.S.B. said that the activities of the six diplomats were “threatening” to Russia’s security and that “signs of spying and sabotage” had been detected in their work.
In a statement, the British Foreign Office said, “The Russian authorities revoked the diplomatic accreditation of six U.K. diplomats in Russia last month, following action taken by the U.K. government in response to Russian state-directed activity across Europe and in the U.K.” It added, “We are unapologetic about protecting our national interests.”
Maria V. Zakharova, a spokeswoman for the Russian Foreign Ministry, said in a statement that her ministry supported the F.S.B.’s decision.
She said that the six British diplomats had been engaged in “subversive work aimed at harming” Russian people. In a separate statement, the Russian Foreign Ministry promised to expel more British diplomats should they engage in similar activities.
Mr. Peskov, the Kremlin spokesman, said on Friday that there was “no talk” about a complete closure of the British Embassy in the Russian capital.
Russian state television showed pictures of the six diplomats and identified them, although the names have not been confirmed. The diplomats had met with Russian civil society activists, the TV report said.
In 2018, Russia expelled 23 British diplomats and shut down the British Council, an organization devoted to international cultural and educational opportunities, in the country after London sent home the same number of Russian diplomats. That came amid a diplomatic crisis touched off by a nerve agent attack in Britain against a Russian former intelligence agent.
While Moscow and London have shared hostility toward each other for years, the relationship worsened after the Russian invasion of Ukraine in 2022. Britain is habitually portrayed by Russian state television as among the most aggressive and Russophobic states in the West.
Stephen Castle contributed reporting from London.
