The base has been central to Moscow's military campaign in Syria
Vladimir Putin has signed a law ratifying a deal with the Syrian government allowing Russia to keep its air base in Syria for almost half a century, official documents show.
The original deal, signed in Damascus in January, sets out the terms under which Russia can use its Hmeimim air base in Lattakia Province which it has used to carry out air strikes against forces opposing President Bashar al-Assad.
The Russian president approved the agreement on Wednesday, after the two chambers of the Russian parliament backed it earlier this month, according to the government's official information portal.
The document says Russian forces will be deployed at the Hmeimim base for 49 years with the option of extending that arrangement for 25-year periods.
— TASS (@tassagency_en) July 27, 2017
The base has been at the heart of Moscow's military foray since it intervened in the conflict in September 2015, helping turn the tide in favour of Assad, one of Russia's closest Middle East allies.
Last month, Assad made his first visit to the air base, located in western Syria.
"The Syrian people will not forget that its Russian brothers stood next to them in this national war," Assad wrote in a visitors' book at the base, state news agency SANA reported.
Photos showed the Syrian leader in the cockpit of a Russian Sukhoi SU-35 warplane, and inspecting an armoured vehicle at the base near Lattakia. He was accompanied by Russian chief of staff General Valery Gerasimov, SANA said.