LONDON — Russia has revoked the accreditation of six British diplomats and accused them of spying on Moscow, it emerged Friday, a fresh geopolitical escalation that was publicized in Russian state media just as London and the US consider allowing Ukraine to strike targets inside Russia.

Moscow’s Federal Security Service (FSB) claimed without providing evidence that it had detected “signs of intelligence and subversive work” by the diplomats, and said it considered their actions “threatening the security of the Russian Federation.”

Britain later said the expulsion occurred last month, and described the accusations as “completely baseless.” The diplomats left Russia weeks ago, and the British government is in the process of replacing them.

The move was revealed hours after British Prime Minister Keir Starmer arrived in Washington DC for meetings with US President Joe Biden about easing restrictions on Ukraine’s ability to strike Russian territory with Western weapons.

Russia claimed Britain’s Foreign Office had transformed since Moscow’s invasion of Ukraine into a body whose “main task is to inflict a strategic defeat on our country.”

Russian state media later reported the identities of the six diplomats the country had expelled.

The Foreign Office said in a statement on Friday that the expulsions were made in response to new measures announced by Britain’s previous government in May. That month, Rishi Sunak’s administration summoned the Russian ambassador and expelled the Russian defense attaché, describing him as “an undeclared military intelligence officer.”

“The accusations made today by the FSB against our staff are completely baseless,” Britain’s Foreign Office said Friday.

“We are unapologetic about protecting our national interests,” it added.

The delayed publicization of the move in Russia was no doubt timed to coincide with Starmer’s meeting with Biden, which itself follows a visit by Britain’s Foreign Secretary, David Lammy, to Kyiv, where he and US Secretary of State Antony Blinken met with Ukrainian President Volodymyr Zelensky.

Zelensky’s government has been pressing both countries to allow the Ukrainian military to fire long-range Western weapons deep into Russian territory, after Kyiv’s surprise incursion into the Russian border region of Kursk.

Russian President Vladimir Putin warned NATO alliance leaders on Thursday that a move to lift the restrictions would be considered an act of war.

“This will mean that NATO countries – the United States and European countries – are at war with Russia. And if this is the case, then, bearing in mind the change in the essence of the conflict, we will make appropriate decisions in response to the threats that will be posed to us,” Putin told reporters.

Britain and Russia have traded diplomatic curbs and sanctions since Russia’s invasion of Ukraine, with Moscow frequently making tit-for-tat moves at critical junctures in its war with Ukraine. Russia has banned a number of British lawmakers, officials and journalists from entering its territory in the past two years. — BBC