A spokesman for Turkish President Recep Tayyip Erdogan said Wednesday the American response to the detention of Pastor Andrew Brunson is an “unacceptable” attempt to interfere with the Turkish legal system.

“There is rule of law in Turkey and the Andrew Brunson case is a legal issue. There is an ongoing legal process related to this individual. It goes without saying that we find unacceptable the disregard of the legal process by the United States, which has been making certain demands,” Erdogan spokesman Ibrahim Kalin told Reuters.

Kalin said statements such as U.S. National Security Adviser John Bolton’s warning that Turkey made a “big mistake” by holding Brunson were “arbitrary” threats and demands.

“His statement is proof that the Trump administration is targeting a NATO ally as part of an economic war,” Kalin said in response to Bolton’s remarks. Later he reiterated that America’s recent actions against Turkey violate the “principles and values” of the NATO alliance.

Kalin further argued that the Trump administration “intends to use trade, tariffs, and sanctions to start a global trade war.”

“Turkey has no intention of starting an economic war with any party. It cannot, however, be expected to keep silent in the face of attacks against its economy and judiciary,” he said.

The presidential spokesman was particularly incensed by the U.S. Treasury Department’s investigation into Turkey’s state-owned Halkbank, which has been accused of violating sanctions against Iran.

“It is unacceptable that certain baseless and false allegations are made against Halkbank to weaken this public bank. It seems that the purpose of those steps is to discredit respectable institutions and persons, and to punish them unjustly rather than discover the truth,” Kalin alleged.

The U.S. Treasury Department has been investigating Halkbank for laundering hundreds of millions of dollars in Iranian money through the American financial system. The scheme, which has been described as one of the biggest sanctions-evading operations in history, involved holding Iranian oil money in escrow, then using the escrow money to buy gold and send it to Iran.

The deputy CEO of the bank was arrested in New York in March for his role in the scheme. The bank officially denies participation in sanctions-busting efforts.

Erdogan’s government asked the U.S. government last week to drop the Halkbank investigation as a goodwill gesture to obtain Paston Brunson’s release. The Trump White House strongly rebuffed this demand.

“A real NATO ally wouldn’t have arrested Brunson in the first place,” a White House official pointed out on Friday, possibly inspiring the Erdogan spokesman’s reciprocal rant about how U.S. sanctions against Turkey violate the principles of NATO.