Russia has threatened to resume full-scale bombing of the besieged eastern half of Aleppo if rebel forces continue their bloody attacks against parts of the city controlled by the Syrian regime.

Russian cut back its airstrikes on Aleppo in mid-October to allow for a “humanitarian pause” and said civilians and rebel fighters could leave the city in safety.

But the Kremlin said Tuesday that it could bring the pause to an end in response to a massive counter-offensive launched by rebel fighters at the end of last week.

"At the moment the pause is continuing, the exit of the civilian population from eastern Aleppo is being enabled, conditions are being created for humanitarian aid,” Dmitry Peskov, a Kremlin spokesman said.

"But all that is impossible if the terrorists continue to fire on neighbourhoods, humanitarian aid routes, launch attacks, and continue to hide behind a [human] shield. That will not permit the continuation of the humanitarian pause."