ISTANBUL >> An American pastor who had been jailed in Turkey for more than 1 ½ years on terror and espionage charges was released today and put under house arrest as his trial continues.

Andrew Craig Brunson, 50, an evangelical pastor originally from Black Mountain, North Carolina, was let out of jail to serve home detention because of “health problems,” Turkey’s official Anadolu news agency said.

Anadolu’s report did not specify the nature of Brunson’s health problems. He was arrested in December 2016 and had been in custody since then.

A court in western Izmir province said Brunson would be electronically monitored and barred from leaving his house. He also is prohibited from leaving Turkey, where he has lived for 23 years and served as pastor of Izmir Resurrection Church.

If convicted, he 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 strongly denies the charges.

The case has strained ties between NATO allies Turkey and the United States. U.S. Secretary of State Mike Pompeo welcomed the news of Branson’s release from jail on Twitter, but called on Turkish authorities to drop the charges.

“We have seen no credible evidence,” Pompeo wrote.

President Donald Trump has repeatedly demanded Brunson’s release and said on Twitter last week that the pastor’s detention was “a total disgrace.”

“He has done nothing wrong, and his family needs him!” Trump tweeted.

U.S. Commission on International Religious Freedom Vice Chair Kristina Arriaga urged the Trump administration and Congress to “respond strongly and swiftly with targeted sanctions” if Turkey fails to give Brunson his freedom after having “deprived this innocent man of his due process rights and liberty.”

Turkish President Recep Tayyip 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 the 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.

U.S. senators have pushed to delay Turkey’s acquisition of American-made F-35 fighter jets, citing Brunson’s case and the Russian S-400 missile system Turkey has agreed to buy.

At the end of a recent hearing, the court inside a prison complex in the town of Aliaga in western Turkey rejected Brunson’s lawyer’s request that he be freed pending the outcome of the trial. The case was adjourned until Oct. 12.