Russia has dismissed the Royal Navy's new aircraft carrier as "just a convenient, large maritime target".
Russian Defence Ministry spokesman Maj Gen Igor Konashenkov was hitting back at the UK for criticism of Russia's ageing carrier Admiral Kuznetsov.
HMS Queen Elizabeth set sail on Monday from Rosyth dockyard in Scotland.
Later UK Defence Secretary Michael Fallon called the Admiral Kuznetsov "old, dilapidated". The ship sailed through the English Channel last year.
The 26-year-old Kuznetsov rarely goes anywhere without a naval tug, in case it breaks down.
Last October it was part of a Russian flotilla that sailed to Syrian coastal waters via the North Sea, English Channel and Mediterranean.
The thick, black smoke belching from the giant Soviet-era ship attracted some mockery on social media.
Planes flew bombing raids over Syria from the Admiral Kuznetsov - making it in Mr Fallon's words "a ship of shame". It is the only carrier in the Russian navy.
Russian airpower has given Syrian President Bashar al-Assad considerable muscle in his offensive against rebel groups, some of which are backed by the West.
Russians 'will admire'
Maj Gen Konashenkov said Mr Fallon's "exalted statements" about HMS Queen Elizabeth "demonstrate a clear lack of knowledge of naval science".
"Unlike the Admiral Kuznetsov aircraft carrier, fitted with air-defence, anti-submarine and, most importantly, Granit anti-ship missile systems, the British aircraft carrier is just a convenient, large maritime target," he said.
At a cost of £3bn (€3.4bn; $3.8 billion) HMS Queen Elizabeth is the most powerful ship ever built for the Royal Navy. Its sister ship, HMS Prince of Wales, is also being built at Rosyth.
Writing in the Daily Telegraph, Mr Fallon said "when you saw that old, dilapidated Kuznetsov sailing through the Channel, a few months ago, I think the Russians will look at this ship [HMS Queen Elizabeth] with a little bit of envy."
"We will take every precaution to make sure that they don't get too close, but I think they will be admiring her," he added.