American pastor Andrew Brunson was released from prison in Turkey on Wednesday after being imprisoned for more than a year and a half on terrorism charges, according to the U.S. State Department.

The details: Secretary of State Mike Pompeo called it a "positive development," but added, "it is not enough. We have seen no credible evidence against Mr. Brunson, and we call on Turkish authorities to resolve his case immediately in a transparent and fair manner." Axios has previously reported that senior Trump administration officials assume Turkish President Recep Tayyip Erdogan is using Brunson to force the U.S. to extradite Fethullah Gulen, a Turkish dissident living in Pennsylvania who Erdogan believes has been organizing a revolution against him.

President Trump has called for the release of Brunson twice this year calling it a "total disgrace" that Turkey has not released the pastor.

Brunson, 50, an evangelical pastor from North Carolina, had denied the charges. The Associated Press reports that if convicted, he could face up to 15 years in prison for the failed coup attempt. Brunson could also get another 20 years if found guilty of espionage.