Two weeks later, in mid-December 2018, Mr. Trump and Mr. Erdogan spoke by phone. The president began by assuring Mr. Erdogan that the government and Halkbank were close to a resolution, and Mr. Erdogan expressed his appreciation, according to Mr. Bolton.
In Turkey around this time, Mr. Erdogan told reporters that Mr. Trump, in an earlier conversation about Halkbank, had assured him that Mr. Trump “would instruct the relevant ministers immediately” to take care of the matter.
Mr. Bolton said in the interview that his concern, as he listened to these conversations, was that Turkey and Halkbank now “had a direct channel in the Oval Office — they weren’t going to negotiate in good faith” with the prosecutors. “Why should they?”
Mr. Trump asked Mr. Bolton to speak with Mr. Whitaker, the acting attorney general at the time, about the case — a move Mr. Bolton said he did not make, although he added that he did not know if someone else from the White House did.
On Dec. 14, the day of the telephone call between Mr. Erdogan and Mr. Trump, the Justice Department notified the Southern District that Mr. Mnuchin, Secretary of State Mike Pompeo and the attorney general’s office would become more involved in the Halkbank case, one Justice Department official said.
The prosecutors in Manhattan had just drafted a memo for Mr. Whitaker and Rod J. Rosenstein, the deputy attorney general, detailing why the Justice Department should give them the authority to file criminal charges against the bank, two lawyers said.
Mr. Rosenstein was convinced that the evidence was compelling, perhaps even more so than in other sanctions-evasion cases in which the United States had charged banks, lawyers familiar with the investigation said. The memo from the prosecutors also noted that the actions Halkbank was accused of taking were helping to support Iran’s economy, which was antithetical to Mr. Trump’s foreign policy goal of tightening economic pressure on the country.
