UK Interior Minister James Cleverly has announced a package of sanctions targeting Russia’s diplomatic presence in the country in response to what he called Moscow’s “malign activity.” He outlined the measures while addressing Parliament on Wednesday.

The measures include imposing new restrictions on Russian diplomatic visas, including capping the length of time Russian diplomats can spend in the UK, and removing the status of diplomatic premises from several Russia-linked properties in the country. London believes that Moscow has used the properties, including Seacox Heath in Sussex and the Trade and Defense Section in Highgate, for intelligence purposes.

Cleverly also announced the expulsion of the Russian defense attaché, whom London has branded an “undeclared military intelligence officer.”

The minister said that the senior diplomat was linked to a recent arson attack on a commercial property in London owned by a Ukrainian national. While the investigation into the case is ongoing, Cleverly noted that other instances “of malign activity carried out both here and abroad” gave him enough evidence to take action. These allegedly include several cases where individuals were charged with conspiring to commit espionage activities on behalf of Russia and a number of “cyber activity incidents” that the UK blamed on Russia’s Federal Security Service (FSB).

“These activities bear all the hallmarks of a deliberate campaign by Russia. We are taking action to send a strong deterrence message to Russia and to further reduce the ability of the Russian Intelligence Services to threaten the UK. We will stand firm in the face of the Russian threat to the UK and our way of life,” Cleverly declared. He added that London has summoned the Russian ambassador to inform him of the new measures officially.

READ MORE: Russia issues military ultimatum to UK

Commenting on Cleverly’s announcement, Russian Foreign Ministry spokeswoman Maria Zakharova said that “Russia will come up with an appropriate response.” She did not elaborate on what that might entail.

The UK has introduced numerous sanctions on Russian companies and individuals since the start of the Ukraine conflict, in which London has firmly sided with Kiev. Tensions between London and Moscow escalated further earlier this week following remarks by British Foreign Secretary David Cameron to Reuters that Ukraine had the right to use long-range missiles provided by his nation to attack targets deep inside Russia. The statement prompted Moscow to warn London that if such strikes were to occur it would retaliate against British targets in Ukraine or beyond.