Oregon Senator Ron Wyden, the ranking member on the Senate Finance Committee, wrote to U.S. Treasury Secretary Steven Mnuchin asking if Trump or anyone acting on the president’s behalf had asked Mnuchin to “handle, intervene, or otherwise engage with Turkish concerns related to Halkbank, or with Halkbank generally?”

Wyden said he was launching an investigation to examine the relationship between Halkbank and Trump administration officials. The letter cited an Oct. 16 Bloomberg report that Trump told Turkish President Tayyip Erdogan in April that Mnuchin and U.S. Attorney General William Barr would handle the Halkbank issue.