President Trump says the United States will impose sanctions on NATO ally Turkey over a detained American pastor held on terror and espionage charges. Shortly after the possibility of sanctions was first announced by Vice President Mike Pence Thursday, Mr. Trump wrote on Twitter that the U.S. "will impose large sanctions on Turkey for their long time detainment of Pastor Andrew Brunson."

The United States will impose large sanctions on Turkey for their long time detainment of Pastor Andrew Brunson, a great Christian, family man and wonderful human being. He is suffering greatly. This innocent man of faith should be released immediately! — Donald J. Trump (@realDonaldTrump) July 26, 2018

"He is suffering greatly. This innocent man of faith should be released immediately!" the president added from aboard Air Force One as he flew to Iowa for an event.

Turkey's foreign minister, Mevlut Cavusoglu, quickly responded, also via Twitter: "No one dictates Turkey. We will never tolerate threats from anybody. Rule of law is for everyone; no exception."

Ministry of Foreign Affairs spokesperson Hami Aksoy added in a separate statement. "In order to improve its relations with the United States, our country has displayed necessary political will and did its part more than enough. It is impossible to accept the U.S. Administration's threatening messages, which totally disregard our alliance and friendly relations between our countries."

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Aksoy added, "As regards the Brunson case, necessary information has been provided to our U.S. counterparts on various occasions and it has been clearly expressed that this issue is totally within the competence of the independent Turkish judiciary. We invite the U.S. Administration to leave aside this wrongful rhetoric and come back to the existing framework of constructive dialogue that we have been engaged in so far."

Pence's initial announcement of possible sanctions came at the close of a three-day conference on religious freedom. Pence warned if Turkey did not take "immediate action" to free Brunson, the U.S. would move to impose "significant" sanctions.

Brunson, 50, an evangelical Christian pastor originally from North Carolina, was let out of jail Wednesday, after 1 1/2 years, to serve house arrest because of "health problems," according to Turkey's official Anadolu news agency.

"Brunson is an innocent man, there is no credible evidence against him," Pence said.

Mr. Trump said on Twitter last week that the pastor's detention was "a total disgrace." One of Brunson's attorneys is Jay Sekulow, who also represents Mr. Trump in the Russia investigation.

If convicted, Brunson faces up to 15 years in prison for "committing crimes on behalf of terror groups without being a member," references to outlawed Kurdish militants and the network of a U.S-based Muslim cleric blamed for a failed coup attempt. He could receive another 20 years if he is found guilty of espionage. Brunson denies the charges.

U.S. senators previously pushed to block the sale of F-35 jets to Turkey, citing Brunson's detention as one instance of Turkish President Recep Tayyip Erdogan's disregard for the rule of law.

Pence's announcement of possible sanctions was delivered at a conference on religious freedom in Washington. Secretary of State Mike Pompeo also spoke at the conference. Pence highlighted cases of what he said was religious repression in Nicaragua, Iran, North Korea, China and Myanmar. He also condemned Islamic State group violence toward religious minorities and what he described as rising anti-Semitism in Europe.

Pompeo announced additional aid for a region of Iraq previously held by the Islamic State group. Pompeo said the department would provide $17 million for de-mining efforts in Nineveh, an area of Iraq historically home to many of Iraq's religious minorities.

Ties between NATO allies Turkey and the United States have been strained by the Brunson case.

Erdogan has previously linked Brunson's return to the U.S. to the extradition of cleric Fethullah Gulen, the cleric Turkey's government holds responsible for a failed July 2016 military coup.

Gulen, who denies orchestrating the coup attempt, lives in Pennsylvania. Turkish requests for his arrest and extradition have not been granted.

Brunson served as pastor of Izmir Resurrection Church, a small Protestant congregation, and has lived in Turkey for 23 years. He was detained by Turkish forces in the aftermath of the failed coup, The indictment against him contends he worked to convert Kurds to Christianity to sow discord in Turkey.

More than 77,000 people were arrested across Turkey after the government declared a state of emergency following the failed 2016 coup. The crackdown has targeted journalists, activists and opposition figures.

Brunson rejected evidence against him during a recent hearing, according to Turkey's state-run Anadolu Agency.

"I believe in and support Turkey's territorial integrity," he told the court. "I forgive those who lie and bear false witness against me."

Brunson's case has been adjourned until Oct. 12.