Foreign secretary Boris Johnson will warn Russia that the UK will retaliate against cyber attacks in a rare visit to Moscow today.
Johnson will tell his Russian counterpart Sergei Lavrov that "the UK will continue to defend its interests where they, and those of its allies, are threatened amid concerns that hostilities between Russia and the West are the highest since the end of the Cold War," according to a Foreign Office statement.
However, the Foreign Office also emphasises that Johnson will "encourage cooperation on joint international challenges", citing the Second World War and the Iran nuclear deal as the fruits of prior Anglo-Russian labours, according to its statement.
The National Cyber Security Centre has warned against the threats of Russian cyber attacks. Ciaran Martin, CEO of the body, said: "Russian interference... has included attacks on the UK media, telecommunications and energy sectors."
The NCSC has also issued guidance that effectively bans the use of Kaspersky antivirus on government computers.
Prime Minister Theresa May herself has accused her Russian counterpart Vladimir Putin of spreading fake news and disarray in a November speech, saying: "We know what you are doing and you will not succeed."
Cybersecurity is only one of several issues Johnson and Lavrov expect to discuss, with Syria, Iran, North Korea and the 2018 World Cup also on the docket for the first UK foreign sec visit to the land of beef stroganov for five years. ®