Russia's defence ministry said on Tuesday that the Syrian army had made a breakthrough in Aleppo in the last 24 hours and dramatically altered the situation on the ground, Russian news agencies reported.

"During the last 24 hours, thanks to very well-prepared and careful actions, Syrian solders were able to radically change the situation," said Major-General Igor Konashenkov, a defence ministry spokesman, according to the Interfax news agency.

"Practically half of the territory occupied by rebels in recent years in the eastern part of Aleppo has been completely liberated," he said.