A spokesman for İşbank, a private lender, said the bank had temporarily suspended use of the payment network while it evaluated new guidelines from the US. DenizBank, another private lender, also suspended Mir’s operations in Turkey by freezing its payment system late last week, according to a person familiar with the matter. The move comes after warnings, first reported in the Financial Times last week, that Western officials planned to step up pressure on Turkey over possible tax evasion of sanctions in the country and viewed the Mir system as a potential backdoor for illicit financing. Guidance later published by the US Treasury Department warned non-US banks entering into new or expanded agreements with the payments network operator would “risk supporting Russia’s efforts to evade US sanctions”. İşbank and DenizBank are among five Turkish banks, along with state-owned VakıfBank, Ziraat Bank and Halkbank, that are members of the Mir payment system developed by Russia’s central bank as a domestic alternative to Visa and Mastercard. Two of them – UAE-owned DenizBank and Halkbank – signed up to Mir after Vladimir Putin launched his full-scale invasion of Ukraine in February.

VakıfBank said it had seen the reports of İşbank’s decision to suspend Mir operations, but added that there was no immediate change in its policies. Halkbank and Ziraat Bank did not immediately respond to a request for comment after business hours. Turkish officials have insisted that while their country has not signed up to Western sanctions aimed at punishing Putin for the invasion, they will not allow their country to become a hub for sanctions evasion. But President Recep Tayyip Erdogan has alarmed US and EU officials with promises to deepen economic cooperation with Moscow. Erdogan, whose country has been a member of NATO since 1952, has condemned the Russian invasion of his neighbor and a company co-owned by his son-in-law has supplied armed drones to the Ukrainian armed forces. He also acted as a mediator, helping secure a deal that allowed more than 3.6 million tons of grain to be exported from Ukrainian ports previously blocked by the Russian military. But the Turkish president has also courted closer ties with Russia, which is a critical natural gas supplier to his country. Last week, he was pictured walking arm-in-arm with Putin at a Shanghai Cooperation Organization meeting in Uzbekistan. He said Turkey would seek to join the China-led club – a move that, if successful, would make his nation the first NATO member state to join the alliance.