Turkish gold trader Reza Zarrab is shown in this courtroom sketch as he appears in Manhattan federal court last April. Photo: Reuters/Jane Rosenberg

There is no end in sight to the diplomatic row between Washington and Ankara, with new word on one of the many areas of friction coming out this week.

A US Federal Bureau of Investigation official involved in the probe of an alleged Turkish-Iranian scheme to violate sanctions said on Tuesday that Ankara had been pushing to have the defendants on trial in connection with the case released.

“High-level foreign officials like Turkey’s ministers of justice and foreign affairs and Turkey’s President [Recep Tayyip] Erdogan exerted diplomatic pressure. They lobbied the Department of Justice, the State Department and even the White House to release [Reza] Zarrab and [Mehmet Hakan Atilla] without a trial,” FBI special agent Jennifer McReynolds said, as reported by Washington-based Al-Monitor.

The agent added: “The implications of this investigation are far from over. Many other co-conspirators are indicted who have not yet been brought to justice.”

Turkey and the United States are embroiled in a multifaceted diplomatic crisis that spans political and security concerns alike.

In addition to efforts to get Zarrab and Atilla released, Ankara has been pushing to have Fethullah Gulen extradited from the United States. Turkish authorities say the 2016 coup attempt was orchestrated by Gulen.

Meanwhile, the administration of US President Donald Trump has been demanding that Ankara release an American pastor implicated by Turkish authorities in terrorist and coup-plotting crimes.

If that were not enough, lawmakers in Washington have passed legislation to block the transfer of F-35 fighter jets to Turkish soil, pending a review of the costs of cutting Turkey out of the F-35 program. The move came in response to Turkey’s purchase of Russian-made S-400 missile systems, a deal that US lawmakers urged Ankara to cancel on a recent trip to Turkey.