A Royal Navy warship has begun monitoring two Russian naval vessels as they transit through the English Channel, as Boris Johnson met with Ukrainian president Volodymyr Zelensky amid what the pair described as “ongoing Russian aggression”.

The French military said on Monday that it had monitored two Russian ships, the Soobrazitelniy and the Stoykiy, and had now handed over the responsibility to HMS Argyle, a Type 23 frigate, and the US Navy’s USS Roosevelt.

A spokesperson for the Ministry of Defence described the tasking as a “normal response”, adding: “As part of a unified response with our allies, the Royal Navy monitor the presence of Russian naval ships as they transit through the English Channel.”

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Tass, Russia’s state news agency, reported on January 24 that the two Russian vessels had left Kaliningrad to conduct “combat exercises”.

HMS Argyll has been tasked to monitor two Russian vessels (Royal Navy/PA)

A joint statement issued following Mr Johnson’s meeting with Mr Zelensky outlined how the UK stands “shoulder to shoulder with Ukraine in the face of ongoing Russian aggression”.

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The statement, released by the offices of the Prime Minister and the president, said: “The Prime Minister emphasised the United Kingdom’s unwavering commitment to Ukraine’s sovereignty, independence, and territorial integrity within its internationally recognised borders.”

At a joint press conference with the Ukrainian president, the Prime Minister warned Russia that the United Kingdom will hit Moscow with sanctions the “moment the first Russian toecap crosses further into Ukrainian territory”.