A British warship and three RAF Typhoons will keep “a close eye” on a Russian aircraft carrier and other ships as they sail past the UK.
The carrier Admiral Kuznetsov and other Russian ships are passing through the English Channel on their way back to Russia from Syria.
A Royal Navy Type 23 frigate, HMS St Albans, was dispatched to meet it as it neared British waters.
The Ministry of Defence said the ships would be “escorted all the way”.
Defence Secretary Michael Fallon said: “We will keep a close eye on the Admiral Kuznetsov as it skulks back to Russia; a ship of shame whose mission has only extended the suffering of the Syrian people.
“We are man-marking these vessels every step of the way around the UK as part of our steadfast commitment to keep Britain safe.”
The Admiral Kuznetsov, the only carrier in the Russian navy, is being accompanied by a nuclear-powered Kirov-class battlecruiser – the Pyotr Velikiy, and a salvage tug.
The Kuznetsov carrier group passed through the Channel last autumn on its way to the Mediterranean.
It joined around 10 other ships off the coast of Syria during Russia’s bombardment of what it said were anti-government rebels in Syria.
The Ministry of Defence said that at 12:30 BST on Wednesday, the returning Russian ships were off the coast of Dover.
A Navy spokesman said the British craft were deployed to “provide reassurance to the nations which border the North Sea and English Channel”.
He added: “Remaining at a respectful distance, but keeping the Russian warships clearly visible, Royal Navy sailors keep watch on every movement through their binoculars and use state-of-the-art radars to track the course and speed of the ships as they pass close to the UK.”
Commander Chris Ansell, the commanding officer of HMS St Albans, said the task demonstrated the navy’s commitments to protecting the UK’s waters.
He said: “As an island nation, the security of the seas around our coastline is vital and this sort of task is routine business for HMS St Albans and the Royal Navy, which stands ready at all times to protect UK territorial waters.”