A Russian police officer patrols outside the British embassy building in Moscow on Friday. AFP

The latest East-West tensions unfolded as British Prime Minister Keir Starmer visits Washington for talks that will include Ukraine’s request to use Western-supplied weapons to strike targets inside Russia. President Vladimir Putin has warned that Kyiv’s use of long-range weapons would put Nato at war with Moscow.

Russia’s Federal Security Service said in an online statement that the Foreign Ministry withdrew the British envoys' accreditations, and Russian TV quoted an FSB official as saying it was decided to expel them.

The FSB said it received documents indicating the diplomats were sent to Russia by a division of the UK's Foreign Office "whose main task is to inflict a strategic defeat on our country,” and that they were involved in "intelligence-gathering and subversive activities.” It did not identify the six diplomats.

The FSB warned that if other diplomats are found to be carrying out "similar actions,” it "will demand early termination of their missions” to Russia.

Russian TV said the six diplomats had met with independent media and rights groups that have been declared "foreign agents” — a label Russian authorities have actively used against organisations and individuals critical of the Kremlin.

Foreign Ministry spokesperson Maria Zakharova said in a statement that the diplomats were carrying out "subversive actions aimed at causing harm to our people.”

"We fully agree with the assessments of the activities of the British so-called diplomats expressed by the Russian FSB," she added in an online statement. "The British Embassy has gone far beyond the limits outlined by the Vienna Conventions.”

Kremlin spokesperson Dmitry Peskov said breaking off diplomatic relations with the UK was not on the table right now.

In calling the Russian allegations "completely baseless,” the UK Foreign Office said the expulsions happened weeks ago, linking them to Britain’s decision in May to revoke the credentials of an attaché at Moscow’s London embassy and to impose a five-year time limit on all Russian diplomats in Britain.

"The Russian authorities revoked the diplomatic accreditation of six UK diplomats in Russia last month, following action taken by the UK government in response to Russian state-directed activity across Europe and in the UK,” the Foreign Office said in a statement. "We are unapologetic about protecting our national interests.”

In May, the UK expelled Russia’s defence attaché in London, alleging he was an undeclared intelligence officer, and it closed several Russian diplomatic properties in Britain that it said were being used for spying. About a week later, Russia reciprocated and expelled Britain’s defense attaché.

Associated Press