President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE and Vice President Pence on Thursday vowed to hit NATO ally Turkey with "significant sanctions" if it does not release American pastor Andrew Brunson, who has been detained there for roughly a year-and-a-half.

Pence repeated his calls for Turkish President Recep Tayyip Erdogan to free Brunson "immediately." Brunson was released from prison on Wednesday, but remains under house arrest on charges of espionage and terrorism that he vehemently denies.

"While he is out of jail he is still not free," Pence said, addressing a conference on religious freedom.

ADVERTISEMENT

"And to President Erdoğan and the Turkish government, I have a message on behalf of the president of the United States of America. Release pastor Andrew Brunson now, or be prepared to face the consequences," Pence continued.

"If Turkey does not take immediate action to free this innocent man of faith and send him home to America, the United States will impose significant sanctions on Turkey," he said.

Shortly after Pence finished speaking, President Trump tweeted that the U.S. "will impose large sanctions" on Turkey because of Brunson's detainment. He did not provide specifics on the type of sanctions or timetable for when they would be implemented.

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

The decision to impose sanctions marks an escalation in the response from the Trump administration to Brunson's detainment, which has contributed to tense relations between the U.S. and Turkey.

Brunson has worked in Turkey for 23 years as the pastor of the Resurrection Church. He was detained more than a year ago for an alleged connection to a failed coup against Erdoğan in 2016.

Brunson is accused of aiding the Kurdistan Workers’ Party, which opposes Erdogan and the ruling party, and of having a connection to Fethullah Gulen, an Islamic cleric who Turkey claims orchestrated the coup attempt.

Brunson's imprisonment is one of a number of recent disagreements between the U.S. and Turkish governments.

The two nations have not seen eye-to-eye on military strategy in Syria. The U.S. has backed Kurdish forces in the region, while Turkey views the Kurds as a terrorist group.

Tensions also flared last year when 15 Turkish security officials were charged for attacking protestors outside the Turkish Embassy while Erdogan was in D.C. to visit Trump.

The final version of Congress's fiscal 2019 defense bill included a provision that calls on Turkey “to release wrongfully detained U.S. citizens including Andrew Brunson and Serkan Golge."

The bill also pauses sales of F-35 joint strike fighters to Turkey until there is a new assessment on U.S.–Turkey relations, going against the wishes of Defense Secretary James Mattis James Norman MattisBiden courts veterans amid fallout from Trump military controversies Trump says he wanted to take out Syria's Assad but Mattis opposed it Gary Cohn: 'I haven't made up my mind' on vote for president in November MORE.

Updated at 11:29 a.m.