Russia says ISIL is playing stock markets and investing in businesses around the globe in order to raise cash after its main sources of income were neutralised.
Following "the destruction" of Islamic State of Iraq and the Levant's lucrative smuggling of oil and gas, the "terrorists" have turned to new sources of financial and logistical support, Russia's UN Ambassador Vassily Nebenzia told the Security Council on Thursday.
"The global terrorist tower of Babel has fallen to pieces. However, ISIL cells continue to speak in one tongue and they're successfully coordinating among themselves," Nebenzia said.
ISIL adherents are speculating on stock markets and investing funds "in legal sectors of the economies of a broad array of countries", he said.
This includes tourism and the hospitality industry as well as agriculture, fish farming, pharmacology and construction companies, said Nebenzia.
The armed group "also continues to fight for control over narcotics flows, including from Afghanistan", the Russian ambassador said, adding it "continues to receive revenue from foreign sponsors operating under cover of philanthropic funds, religious organisations and other non-government bodies".
In 2014, ISIL leader Abu Bakr al-Baghdadi proclaimed a "caliphate" in Syria and Iraq after his fighters rapidly routed government forces and took over large swathes of territory.
In recent months ISIL has suffered major military setbacks and lost most of its territory in Syria and Iraq, though fighters continue to control pockets in both.
In his first purported message in a year released on Wednesday, Baghdadi called on followers to "keep fighting your enemy".
The Pentagon said in a recent report as many as 17,100 ISIL fighters remain in Iraq and 14,000 in Syria. The UN estimated of 20,000 to 30,000 ISIL cadres are still in both countries.
At the UN meeting, US Ambassador Nikki Haley urged all countries on Thursday to ensure the armed group faces "an enduring defeat".
UN Undersecretary-General for Counter-Terrorism Vladimir Voronkov said ISIL continues to pose a serious challenge, "especially due to its transformation into a covert network, the activities of its regional affiliates, and the complex threat posed by returning and relocating foreign terrorist fighters and their families".
Voronkov warned the rising threat from the group's fighters "will be diverse and hard to predict".
