Russia revealed that it had in August signed with Syria an agreement giving Moscow the go-ahead for an open-ended military presence in the war-torn country.

The agreement was signed in Damascus on August 26, 2015, more than a month before Russia launched a bombing campaign against the Takfiir group, ISIL (so-called Islamic State in Iraq and Levant), and other "terrorists" at the request of the Syrian government.

The Russian government on Thursday released the text of the agreement, which said that it had been "concluded for an open-ended period of time."

Under the terms of the agreement, Russia deployed warplanes and personnel at the Hmeimim airbase in Latakia in Syrian government-held territory.

The deal was made to defend the "sovereignty, territorial integrity and security of the Russian Federation and the Syrian Arab Republic," according to the document.