Syrian government forces have retaken the largest rebel-controlled district in eastern Aleppo, state media reported on Saturday.
The capture of Masaken Hanano, in north-east Aleppo, could give Syria's army line-of-fire control over other opposition-held areas, activists say.
The government resumed its offensive to retake eastern Aleppo on 15 November. About 0.30 million (275,000) people are under siege.
The assault has killed 212 civilians, the UK-based Syrian Observatory for Human Rights says.
Among the victims were 27 children, the monitoring group added. Reports suggest there is a lack of medical supplies and food.
Capturing all of Aleppo would be a major victory for Syrian President Bashar al-Assad after six and a half years of conflict.
Masaken Hanano was the first neighbourhood in Aleppo taken by rebels in 2012.
Syrian forces, now in "full control" of the district, were clearing the area of mines and bombs, state news agency Sana said.
Soldiers were now just metres away from isolating the northern districts of east Aleppo from the southern ones, Abdel Rahman, from the Syrian Observatory, told a news agency.
The group said other areas of Aleppo were also targeted.
Air strikes launched as part of the recent government offensive were described by activists as the most intense ever, leaving the streets deserted.
Aleppo, once Syria's commercial and industrial hub, has been divided roughly in two since 2012, with the government controlling the west and rebels the east.
In the past year, Syrian troops have broken the deadlock with the help of Iranian-backed militias and Russian air strikes.
Russia says its air force is active in other parts of the country, but not operating over Aleppo.
Meanwhile, Sana also said three people had died and 15 others were injured on Saturday when rebels fired rockets into government-held west Aleppo, Reuters reported; according to BBC.