Islamic State has ramped up sales of oil and gas to the regime of Syrian President Bashar al-Assad, U.S. and European officials said, providing vital fuel to the government in return for desperately needed cash.

The regime’s purchases are helping sustain Islamic State amid unprecedented military pressure on the militant group in both Syria and Iraq. It is also helping the group despite the regime’s insistence that it is dedicated to eradicating the militant group with the help of its top allies Russia and Iran.

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