Russia has expelled six British diplomats, accusing them of espionage, according to the Russian Federal Security Service (FSB).
The agency announced today that the diplomats have been stripped of their accreditation and will be deported.
Russian state television quoted an FSB official, stating that the diplomats were sent by a division of the UK's Foreign Office, whose primary mission is to "inflict a strategic defeat on Russia."
The FSB claimed the diplomats were involved in gathering intelligence and engaging in subversive activities.
This diplomatic move comes just two days after the United States and the UK pledged nearly $1.5 billion in additional aid to Ukraine.
The decision also coincides with renewed calls from Ukrainian officials to use Western-supplied missiles against deeper targets within Russia.