Syrian government troops have gained control of 50% of rebel-held areas of east Aleppo, says a military spokesman.
Gen Samir Sulaiman told the BBC he hoped all of Aleppo would be in government hands within weeks.
Gen Sulaiman was speaking a day after the army seized another district, Tariq al-Bab, from the rebels opposing President Bashar al-Assad.
Swathes of east Aleppo held by rebels have been seized by government troops and militiamen in the past three weeks.
Earlier reports on Saturday had suggested as much as two-thirds of the rebel-held area had been recaptured.
Up to 250,000 people remain trapped in besieged areas of the city, the UN says.
Tens of thousands of people have been displaced. The United Nations this week said conditions in east Aleppo were now so dire that medical operations were being conducted without anaesthetics.
The Syrian Observatory for Human Rights monitoring group said Tariq al-Bab was recaptured more than four years after falling into rebel hands.
Clashes in the district left tens of fighters on both sides killed or injured, it said.
At least 300 people have been killed since the government-led offensive on east Aleppo.
Thousands of people fled Tariq al-Bab into neighbouring areas as fighting intensified.
New push - by Lyse Doucet, west Aleppo
The thunderous boom of shelling can be heard across Aleppo as Syrian warplanes and artillery pound districts to the east.
The army and its allies are advancing rapidly on the ground, Gen Sulaiman told me, and they expect to recapture 60% within days.
Rebel fighters are now regrouping and retreating south to more densely populated areas of their enclave.
UN officials here say they're bracing for another exodus of civilians. Thousands have already fled to this part of Aleppo.
Sources tell me that that Syria's ally Russia is involved in a new effort to co-ordinate with rebel forces to arrange the evacuation of the sick and wounded and allow as many as 1,000 civilian activists who are not involved in the fighting to leave.
But for all the discussions, what's clear to all is the Syrian military and its allies are determined to retake all of Aleppo within weeks.
Earlier this week, Stephen O'Brien, the UN's humanitarian affairs chief, said besieged areas of the city risked becoming "one giant graveyard".
He said some people inside opposition-controlled areas were so hungry they were reduced to scavenging.
On Thursday, Russia, that supports President Bashar al-Assad's government, indicated it was ready to discuss opening four safe corridors for humanitarian access.
Aleppo was once Syria's largest city and its commercial and industrial hub before the uprising against President Bashar al-Assad began in 2011.
It has been divided in roughly two for the past four years. But in the past 11 months, Syrian troops have broken the deadlock with the help of Iranian-backed militias and Russian air strikes.
In early September they reinstated a siege of the east, and launched a large-scale offensive later that month to retake full control of the city.
The Syrian Observatory says more than 300 civilians have been killed in rebel-held districts since the offensive was stepped up in mid-November.