Britain said on Saturday it had tracked in recent days six Russian naval and merchant ships carrying ammunition used in Syria as they sailed through the Channel.
The British defense ministry said in a statement the ships - shadowed by the Royal Navy and the Royal Air Force - were withdrawing from Syria following the ousting of its president, Bashar al-Assad, a close Russian ally, in December.
Russia has been evacuating its military assets from Syria since Assad's overthrow, the ministry said, describing it as a "blow to (Moscow's) ambitions in the Middle East".
"These ships were retreating from Syria after Putin abandoned his ally Assad, yet they were still armed and full of ammunition," said defense minister John Healey, Reuters reported. "This shows Russia is weakened but remains a threat."
Russia hopes to retain the use of naval and air bases in Syria under the new Islamist leadership that took power after Assad fled to Moscow following 13 years of civil war in which Russian troops had intervened on his behalf.
Britain's defense ministry said the withdrawal of ammunition from Syria showed that Russia's prioritisation of its war in Ukraine had affected its capability to keep Assad in power.
Russia's President Vladimir Putin held a phone call with Syria's interim leader Ahmed al-Sharaa on Wednesday, the first call between the two men since Assad's fall.
The Syrian presidency said Putin had invited Syria's new foreign minister to visit Moscow and had told Sharaa that Moscow was ready to reconsider bilateral deals signed under Assad.
