U.S. Leans on Turkey to Stop Supporting Hamas and Russia

ISTANBUL—The Biden administration’s sanctions chief warned Turkish officials that the country is fueling violence across two continents by serving as a financing haven for Hamas and a trade hub for Russia’s war machine.

Despite U.S. sanctions targeting Hamas financiers over the past decade, Turkey has allowed the group’s investment firms, holding companies, real-estate brokerages and a host of other businesses to function out of Istanbul, U.S. officials say.