This was reported by Reuters with reference to sources, reports Ukrinform.
Two military sources told the newspaper that Russia had promised Damascus additional military aid to prevent the rebels from advancing. New equipment will begin arriving within the next 72 hours.
In addition, it is noted that the Syrian army received an order to "safely withdraw" from the main areas of the city, which the rebels entered.
The rebels launched an offensive in the direction of Aleppo on Wednesday, and by the end of the day on Friday, according to the operational headquarters, their forces had entered various areas of the city.
The commander of the Jaish al-Izza rebel brigade, Mustafa Abdul Jaber, said that the lack of manpower of the Iranian-backed enemy contributed to the rapid advance. Iran's allies in the region have suffered a series of strikes from Israel amid the fighting in Gaza.
Opposition forces said the campaign was in response to increased airstrikes by Russian and Syrian air forces on civilians in rebel-held Idlib province in recent weeks, as well as to prevent attacks by the Syrian army.
On November 29, opposition forces in Syria entered the country's second largest city, Aleppo.