Russia has begun establishing a permanent presence at its military bases in Tartus and Hemeimeem in Syria, Russian Defense Minister Sergei Shoigu said Tuesday.

"Last week the Commander-in-Chief approved the structure and the bases in Tartus and in Hemeimeem. We have begun forming a permanent presence there," he said.

The Federation Council — Russian parliament's upper house — has reviewed a document that suggests upgrading Tartus naval supply facility to a full naval base.

The document determines procedures for the entry of Russian warships into Syrian ports, their registration and movement of military equipment. It would allow up to 11 Russian warships, including nuclear-powered ones to stay in Tartus.

Expenditures for expanding the base will amount to 3.2 billion rubles ($55.4 million) a year. The agreement is valid for 49 years with a possibility of its automatic extension for 25-year periods.

During his visit to the Hemeimeem base on Dec. 11, President Vladimir Putin said Russia will keep the air base as well as a naval facility at the Syrian port of Tartus while announcing a partial pullout of Russian forces from the war-torn country. Russian Defense Minister Shoigu said on Dec. 22 that Putin's order was fulfilled.

Putin's brief stop at the Hemeimeem Air Base in Syria's coastal province of Latakia came days after Russia announced the liberation of Syria from the Daesh terrorist group — a claim disputed by war monitor Syrian Observatory for Human Rights. The Hemeimeem Air Base has served as the main foothold for the air campaign Russia has waged since September 2015 in support of the regime.

Russia had previously announced a partial drawdown of its forces in Syria in March last year. However, a powerful Russian contingent remained in place and there was little sign of operations being scaled back.

Syria has been locked in a vicious civil war since 2011, when the Assad regime cracked down on pro-democracy protests with unexpected ferocity. Since then, hundreds of thousands of people have been killed in the conflict, according to the U.N.