President Donald Trump urged then-Secretary of State Rex Tillerson to convince the Department of Justice to drop charges against a client of Rudy Giuliani during a meeting in the Oval Office in 2017, Bloomberg reported Thursday.Tillerson refused, saying the action would be illegal and constitute interference in an ongoing investigation. Three sources who spoke with Bloomberg on condition of anonymity said participants in the meeting were shocked at the request.The client, Reza Zarrab, is an Iranian-Turkish gold trader who was charged with evading sanctions on Iran. Zarrab had hired Giuliani and former Attorney General Michael Mukasey to represent him.Tillerson repeated his objections immediately following the meeting to then-Chief of Staff John Kelly.Zarrab’s case also drew the attention of Turkish Prime Minister Recep Tayyip Erdogan. Before Zarrab began cooperating with authorities in his case, Erdogan tried to have him released to Turkey.Giuliani affirmed that he had been speaking with U.S. officials at the time regarding a possible prisoner swap, trading Zarrab for Andrew Bunson, an American pastor who was jailed in Turkey until 2018.Zarrab eventually pleaded guilty in his case and testified against the head of international banking at Turkey’s state-owned Halkbank, Mehmet Hakan Atilla. Atilla was convicted of helping Iran evade U.S. sanctions through money laundering and served 28 months in U.S. prison before returning to Turkey. Zarrab asserted that Erdogan knew of the laundering, which Erdogan has strenuously denied.Erdogan on Tuesday launched an invasion of northeast Syria to resettle Syrian refugees who fled the country’s civil war, a day after Trump announced the withdrawal of American troops from the area. Trump has been accused of abandoning Kurdish allies who fought against ISIS to face Turkey’s military, while Turkey deems Kurdish groups in the region terrorist organizations, citing their ties to militants within Turkey.The White House confirmed that Trump will host Erdogan later this month as part of a state visit. Trump has defended his alliance with Turkey, writing on Twitter that “Turkey is a big trading partner of the United States,” and that the country is an “important” NATO member.