Russia is reportedly close to reaching an agreement with Syria's new leadership that would secure the future of its military bases in the country.

Under the deal, Russia will keep its naval port in Tartus and its air base at Hmeimim, Bloomberg News reported.

The Russian Defense Ministry said it had reached a tacit understanding with Hayat Tahrir al-Sham, the rebel group that led the collapse of the Assad regime on Sunday and is leading efforts to establish a transitional government.

Bloomberg says satellite images show the base appears to be abandoned. Five warships, including three frigates and at least one submarine, were photographed at the port last week but had left by Monday.

Russia has had a naval base in Tartus since 1971, and the facility was expanded in 2012 when Moscow began increasing its support for the Assad regime.

It is Russia's only replenishment and repair point in the Mediterranean, and has become a major launching point for its operations in Africa.

Since the start of its intervention in Syria in 2015, Russia has owned the Hmeimim base, which depends on supplies of weapons and equipment arriving by sea to Tartus, about 60 kilometers to the south.

The Hmeimim base is known to be heavily protected with advanced air defence systems that allow it to cover wide areas in the region.

The base is a key transit point for mercenaries and military advisers heading to Africa, where Moscow is also seeking to boost its influence.

Hayat Tahrir al-Sham led the coalition that entered Damascus on Sunday and overthrew Syrian President Bashar al-Assad.

It is noteworthy that "Hay'at Tahrir al-Sham" is still banned in many Western countries, including the United States, which classifies it as a terrorist organization.