In an interview to be published Thursday by Syrian newspaper al-Watan, early copies of which were given to international media, the Syrian president said, "It's true that Aleppo will be a win for us, but let's be realistic - it won't mean the end of the war in Syria," he said. "But it will be a huge step toward this end."
A terrorist loss in Aleppo "will mean the transformation of the course of the war across Syria," he said, the Middle East Eye reported.
Assad described the city as the "last hope" of terrorists and their backers, "after their failure in the battles of Damascus and Homs".
"The decision to liberate all of Syria is taken and Aleppo is part of it."
A fierce offensive launched last month has seen Syrian forces move closer than ever to retaking all of Aleppo and winning their most important victory yet in the war that began in 2011.
Terrorists, who seized east Aleppo in 2012, have suffered devastating setbacks there in recent days, losing about 80 percent of their former territory, including the historic Old City, said the so-called Syrian Observatory for Human Rights.
Asked about the possibility of a truce in Aleppo, Assad told al-Watan: "It's practically non-existent, of course."
"The Americans in particular are insisting on demanding a truce, because their terrorist agents are now in a difficult situation," he told the paper.
Terrorists have rejected talk of leaving Aleppo, and Assad's government has said it will not agree to any ceasefire without a full terrorist withdrawal.