Britain on Thursday said it had summoned the Russian ambassador in the UK to express its deep concern at what it called Moscow's "pattern of malign activity."
The Foreign, Commonwealth and Development Office (FCDO) said that included "cyber intrusions, interference in democratic processes, and the build-up of military forces near the Ukrainian border and in illegally annexed Crimea."
It came on the same day the United States announced sanctions and the expulsion of 10 Russian diplomats in retaliation for what Washington says was the Kremlin's U.S. election interference, a massive cyber attack and other hostile activity.
The British government said it "made clear the UK's support for the actions announced by President Biden" as Russia's top envoy in London was summoned to see FCDO Permanent Under Secretary Philip Barton.
"He set out the UK assessment that the Russian Intelligence Services were behind the SolarWinds compromise," a FCDO spokesperson said in a statement, referring to a hack last year that cybersecurity experts and Western nations blame on Russia.
"He informed the Ambassador that the UK will continue to work with our allies to call out and counter malign operations by the Russian Intelligence Services."
Barton also stated Britain's concern at the recent build-up of Russian military forces near the Ukrainian border and in Crimea, which Moscow annexed in 2014, the spokesperson added.
"These activities are threatening and destabilizing."
"Russia needs to cease its provocations and de-escalate tensions in line with its international obligations."