Russia has slammed comments by British Defence Secretary Michael Fallon calling Moscow's flagship aircraft carrier Admiral Kuznetsov "a ship of shame".

Fallon on Wednesday said British warships and warplanes tracked Russia's only aircraft carrier through the English Channel.

The carrier and its escort, the guided missile cruiser Petr Velikiy, are on their way back to Russia after participating in airstrikes in Syria. They left the Mediterranean Sea earlier this month, BBC reported.

"We are keeping 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," Fallon said.

The Russian Defence Ministry on Thursday said it had "paid attention" to Fallon's remarks.

"The Russian combat ships do not need escort services," the statement said. "They know the fairway and the course."

The ministry also suggested Fallon should be "paying more attention to the British fleet".

British Foreign Secretary Boris Johnson on Thursday struck a slightly different tone to his defence counterpart, noting Moscow's role in bringing about Syrian peace talks in Astana this week, following on from its military involvement.

"To the extent that the Russians are capable of getting a ceasefire and stopping suffering, that must be rated a plus," Johnson told a House of Lords committee.

"That comes after a pretty brutal and barbaric bombardment of Aleppo and other places which they facilitated — or, I'm sure, perhaps even participated in," he said.

According to the BBC, Johnson said Russia had intervened in Syria "to considerable effect" by preserving the regime of Syrian President Bashar al-Assad.

He described Moscow's involvement there as a "fact of life" after other powers such as Britain had declined to step in.

Russia's airstrikes in support of Assad's forces have been crucial in helping them gain the upper hand in the long-running conflict. In December, they succeeded in pushing rebel fighters from the key city of Aleppo.

Syria's brutal civil war has raged on for nearly six years and killed an estimated 400,000 people.