"In terms of ISIL’ [IS] financial strength, the report notes that despite some loss of revenue due to territorial setbacks, ISIL could sustain its operations through accessible reserves in cash or investment in businesses ranging between $50 million and $300 million American dollars," Voronkov said.
Voronko, briefing the Security Council on a new CTO report, also said IS remains a threat to international security.
"Having a center of gravity in Iraq and the Syrian Arab Republic, where it is reported to control between 14,000 and 18,000 militants, including up to 3,000 foreign terrorists fighters, ISIS [IS] has continued to evolve into a covert network operating at a local level and organizing itself at a provincial level," Voronkov said.
The oil revenues have been one of the principal parts of the terrorists' income. However, since 2015, Daesh's wealth in stolen natural resources in Syria and Iraq has been declining, following a military campaign started by Russian and Syrian air power to destroy smuggled oil heading for the Turkish border. In November 2015, the Russian Aerospace Forces launched a major concentrated attack targeting oil tankers, destroying an estimated 1,000 oil tankers, as well as oil refineries and oil storage facilities in a five-day campaign in northern and eastern Syria. The US-led coalition reported destroying another 280+ tankers later that month, with both sides launching further strikes.
EXCLUSIVE: See How Daesh Stored Its Stolen Oil (VIDEO)
When the terrorists started to dramatically lose the territories they seized in 2016, US analysts estimated that the terrorists were making about $20 million a month from the stolen oil, down from as much as $3 million per day in 2014.
READ MORE: US Helped Daesh in Attempt to Gain Control Over Syria's Oil — Damascus
*Daesh, also known as IS (Islamic State), ISIS, ISIL — a terrorist group, banned in numerous countries, including Russia