LONDON: Daesh militants have made more than $500 million trading oil with significant volumes sold to the government of Syrian President Bashar Assad and some finding its way to Turkey, a senior US Treasury official has said.

In one of the most detailed public explanations of Daesh’s oil trade, US Treasury Department official Adam Szubin said militants were selling as much as $40 million a month of oil at the installations which was then spirited on trucks across the battle lines of the Syrian civil war and sometimes further. “Daesh is selling a great deal of oil to the Assad regime,” Szubin, acting under secretary for Terrorism and Financial Intelligence with the Treasury, told an audience at Chatham House in London.

“The two are trying to slaughter each other and they are still engaged in millions and millions of dollars of trade,” Szubin said of Assad’s government and Daesh.

The “far greater amount” of Daesh oil ends up under Assad’s control while some is consumed internally in Daesh-controlled areas. Some ends up in Kurdish regions and some in Turkey, he said.

“Some is coming across the border into Turkey,” Szubin said when asked for details on the money trail.

“Our sense is that Daesh is taking its profits basically at the wellhead and so while you do have Daesh oil ending up in a variety of different places that’s not really the pressure we want when it comes to stemming the flow of funding — it really comes down to taking down their infrastructure,” he said.

Szubin said it was unclear whether the $40 million a month estimate could be multiplied over a year. But in remarks prepared for delivery, he said Daesh had made more than $500 million from the oil trade, but did not give a more specific time period. “There is no question that better security, closing the Turkish border to flows is a key component right now and we are looking to the Turks to do more in that respect,” Szubin said.

“It’s not just a financial issue — it is about foreign terrorist flows, it’s about weapons and it’s about financing. I think securing that border would pay major dividends in terms of intensifying the pressure and also reducing the threat.”

Meanwhile, a coalition airstrike killed a Daesh finance chief in Iraq last month, the US military said, hailing it as another scalp in its bid to blow apart the extremists’ financial network. Abu Saleh was killed in late November, US military spokesman Col. Steve Warren said in a video conference from Baghdad, calling him “one of the most senior and experienced members” of the group’s nefarious financial system.

“Abu Saleh was the third member of the finance network that we have killed” recently, Warren added, likening him to a finance minister for the extremist group.

Real name Muwaffaq Mustafa Muhammad Al-Karmush, the US State Department’s terrorist blacklist describes him as a 42-year-old Iraqi.