Recep Tayyip Erdogan
Recep Tayyip ErdoganReuters

A spokesman for Turkish President Recep Tayyip Erdogan on Wednesday slammed what he said was the United States' disregard for Turkey's legal process, adding Washington had made arbitrary comments and demands in the case of detained pastor Andrew Brunson.

The spokesman, Ibrahim Kalin, called on the United States to respect Turkey's judicial independence.

"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," Kalin told Reuters.

"It goes without saying that we find unacceptable the disregard of the legal process by the United States, which has been making certain demands."

His comments came after President Donald Trump's national security adviser John Bolton told Reuters earlier that Turkey made a "big mistake" in not releasing Brunson, who has been held by Ankara since 2016 and faces 35 years in prison on espionage and terror-related charges.

President Donald Trump recently imposed sanctions on several Turkish officials and a 20 percent duty on aluminum and a 50 percent duty on steel in response to the continued imprisonment of Brunson.

In response, Turkey imposed tariffs on certain imports from the United States.

On Monday, Trump told Reuters in an interview that he would not make any concessions to Turkey to gain Brunson’s freedom, adding he was not concerned that retaliatory tariffs he imposed will have a ripple effect and hurt the European economy.

Treasury Secretary Steven Mnuchin has said the United States was ready to place more sanctions on Turkey if Brunson is not released.