President Donald Trump (L) speaks withh Turkey's President Recep Tayyip Erdogan ahead of the opening ceremony of the NATO (North Atlantic Treaty Organization) summit, at the NATO headquarters in Brussels, on July 11, 2018.

The Trump administration rejected a proposal from the Turkish government that would free a detained American pastor in exchange for relief of one of its largest banks, The Wall Street Journal reported.

The report, which cites a senior White House official, said Turkey asked the U.S. to drop an ongoing investigation into Halkbank, one of the biggest state-owned Turkish banks. Halkbank faces major fines for allegedly violating U.S. sanctions on Iran.

In exchange, the Turkish government would release Andrew Brunson, an American pastor who has been detained in Turkey since 2016. Turkey accused Brunson of spying and trying to overthrow the government after a failed coup that year. President Donald Trump said Friday the charges against Brunson were "phony," adding "he is not a spy."