The National Security Council asked the Education Department about a network of charter schools, partly funded with federal money, that were said to be linked to Mr. Gulen, the Erdogan rival who was living in Pennsylvania. The agency was then asked if the money could be blocked, one official involved in the conversations said. But Education Department officials resisted, saying they did not have the legal authority to stop the funding.
The White House encountered a similar lack of enthusiasm at the Department of Homeland Security and the F.B.I., which received requests to investigate Mr. Gulen and look for ways to perhaps force him out of the United States, officials involved in the efforts said. The F.B.I. declined to comment.
In the meantime, the effort by Turkey to resolve the Halkbank case intensified.
Records show that the bank and the Turkish government paid Mr. Ballard’s lobbying firm $4.6 million over two years for work on Halkbank and other matters, including meetings and phone calls with the vice president’s office, the State Department, members of Congress and Jay Sekulow, one of Mr. Trump’s personal lawyers.
Mr. Ballard’s team argued that the Halkbank case was a foreign policy matter, and that the need to maintain close relations with Turkey, a NATO member, had to be taken into account.
But the investigation by the federal prosecutors in Manhattan ground ahead. By early 2018, it had led to the indictments of nine defendants, including Turkey’s former economy minister and three Halkbank officials, on charges such as bank fraud and money laundering related to the sanctions-evasion scheme.
One defendant, Mehmet Hakan Atilla, the bank’s deputy general manager for international banking, was tried and, in January 2018, convicted.
Mr. Zarrab, the gold trader, had pleaded guilty and testified about how the scheme had relied on false documents and front companies, and how he had paid millions of dollars in bribes to the economy minister and Halkbank’s general manager.