The protocol signed by Russia and Syria in January 2017 regulates issues related to the deployment of the Russian Air Force on Syrian territory as well as related to Russia’s exercise of jurisdiction over its military movable and immovable assets on Syrian territory.

Under the protocol, the Russian Air Force are allowed to stay on Syrian territory for 49 years with an option of automatically extending that arrangement for 25-year periods after this term expires.

The document, published on the Russian official legal information website, particularly says that the Syrian government is handing over a plot of land in the Latakia province, where the Khmeimim Air Base is located, over to Russia for its free use.

The bill ratifying the protocol was signed by Putin on Thursday, according to a Kremlin statement.

It was adopted by the Russian State Duma, the Lower House of the Russian Parliament, on July 14 and approved by the Senate five days later.

The Russian Air Force was deployed to Syria on September 30, 2015 at the request of the Syrian government as part of the operation aimed at fighting terrorist groups. The group was stationed at the Khmeimim Air Base.

Most Russian troops initially deployed to Syria were withdrawn in March 2016 after Putin said that the objectives of the five-month anti-terrorist operation in Syria were “generally accomplished.” At that time, Russia said it would keep a military presence at the port of Tartus and at the Khmeimim airbase to monitor the situation in the region and observe the implementation of ceasefire agreements.