BEIRUT, Nov 29( Reuters) – Syria and its allies aim to drive rebels from Aleppo before Donald Trump takes office as U.S. President, a senior official in the pro-Damascus military confederation told, as pro-government forces-out surged to their biggest victories in the city for years.

Rebels face one of their gravest moments of the war after pro-government forces-out routed fighters over the past few days from more than a third of the territory they controlled in the city. Thousands of civilians have fled for safety.

The pro-government official, who declined to be identified in order to speak freely, nevertheless indicated that the next stage of the campaign could be more difficult as the army and its allies seek to capture more densely populated areas.

Rebel fighters opposed fiercely to stop government forces-out advancing deeper into the opposition-held enclave on Tuesday, tackling pro-Assad militias who sought to move into the region from the southeast, a rebel official said.

The attack on eastern Aleppo threatens to snuff out the most important urban center of the revolt against President Bashar al-Assad, who has been securely on the offensive for more than a year thanks to Russian and Iranian military support.

Capturing rebel-held eastern Aleppo would be the biggest victory to date for Assad in the conflict that has killed hundreds of thousands of people since it arose out of protests against his regulation virtually six years ago.

Anadolu Agency via Getty Images
A Syrian infant daughter is insured at the scene of the air strikes carried out by the war crafts belonging to Russia and Assad regime forces-out in al-Shear neighborhood of Aleppo, Syria on November 28, 2016.