A Syrian activist says Russian troops have deployed along a main road leading into besieged rebel-held neighborhoods of the northern city of Aleppo ahead of the possible arrival of aid convoys.

Rami Abdurrahman of the Britain-based Syrian Observatory for Human Rights says the Syrian government forces that were stationed there have been replaced by Russian troops. He says aid is expected to enter rebel-held Aleppo later Friday.

Aleppo-based activist Bahaa al-Halaby denies that government troops withdrew from Castello road.

Aid deliveries are part of a U.S.-Russia deal that imposed a cease-fire, which started Monday.

Russia's military announced Thursday evening that Syrian government forces had begun withdrawing from Castello road but did not confirm if Russian troops would be stationed there. The Pentagon said it had no indication of a withdrawal.