How much territory have Russia and Syria recaptured from IS?
Claim: The Syrian Army, backed by Russian air support, has recaptured more than 500,000 sq km of territory from so-called Islamic State (IS) militants.
Reality Check verdict: This is not possible - since it's far more territory than there is in the whole of Syria.
"Some 998 towns and villages have been freed, with the liberated territory covering 503,223 sq km. Most of the militants have been eliminated," Defence Minister Sergei Shoigu said during a speech in the Philippines on 24 October.
However, Syria's total area is just over 185,000 sq km according to the UN - meaning that, for Mr Shoigu's figures to be correct, Syrian troops must have taken back territory amounting to more than two-and-a-half times the country's size.
It is unclear how and why Mr Shoigu gave such an exaggerated figure for the recaptured territory. Reality Check asked the Russian defence ministry to explain the discrepancy, but it had not replied by the time this article was published.
The defence ministry provides regular updates on the progress of the Syrian Army's operation to recapture the country's territory, and the figures it gives are usually somewhat more plausible.
On 30 June, for example, Mr Shoigu announced that government troops had taken back more than 12,000 sq km over the preceding month.
Claims made by the Russian government regarding its activities in Syria have often been subjected to outside scrutiny.
For instance, Moscow has consistently denied that its air strikes have caused any collateral damage or civilian deaths since they began.
However, in September the UK-based Syrian Observatory for Human Rights accused Russia of causing at least 69 deaths over the course of only 72 hours.
Earlier, Medecins Sans Frontieres accused Russia of being behind the February 2016 bombing of a medical facility in the northern Idlib province of Syria.
Moscow denied these allegations, too, blaming the incident on the US-led anti-IS coalition.
Russia began its operation in Syria in September 2015, and immediately began conducting air strikes against what it said were IS targets.
However, Syrian opposition activists alleged that Russia was in fact targeting civilian infrastructure in towns held by anti-government rebels, and the US military later reported that most of Russia's strikes were concentrated in rebel-held Idlib Province, far from the nearest IS stronghold.
Most claims about military operations in Syria are very hard to verify so the Russian Defence Minister's claim about the amount of territory "liberated" from IS is comparatively straightforward to check.