Sen. Bob Corker, chairman of the Senate Foreign Relations Committee, and 65 of his Senate colleagues wrote a letter to Turkey's president demanding the release of imprisoned American pastor Andrew Brunson, who is on trial for spying and aiding terror groups, Politico reported Saturday.

"The United States Government, and millions of Americans deeply concerned by the Brunson case, have been patient, in the hope that justice would be done and Pastor Brunson would be reunited with his family," Corker wrote in the letter to Turkish President Recep Tayyip Erdogan, signed by the group of bipartisan lawmakers and released Friday.

"The signatories of this letter have concluded that other measures will be necessary to ensure that the Government of Turkey respects the right of law-abiding citizens and employees of the United States to travel to, reside in, and work in Turkey without fear of persecution," the letter states.

Brunson faces a maximum of 35 years in prison if convicted, NBC News reported Friday. Turkey claims Brunson worked with an Islamic preacher living in Pennsylvania, Imam Fethullah Gülen, whom Erdogan accused of orchestrating an attempted coup in the summer of 2016. Brunson has been jailed since October 2016.

Brunson, who has lived in Turkey for more than two decades, ran a Protestant church in southwestern Turkey, NBC reported. Of the charges, Brunson denied them and said as his trial began on Monday, "I've never done something against Turkey … I love Turkey. I've been praying for Turkey for 25 years."

The senators wrote the charges were based on an "absurd collection of anonymous accusations, flights of fantasy, and random character assassination."

President Donald Trump on Thursday also called for Brunson's release, tweeting, "They call him a Spy, but I am more a Spy than he is. Hopefully he will be allowed to come home to his beautiful family where he belongs!"

Sen. Thom Tillis, R-N.C., traveled to Turkey for part of the trial and explained Brunson feared his case would be forgotten.

"I heard that he was really concerned that maybe the American people would look at the indictment and believe it and forget him," Tillis told the Raleigh News & Observer. "It was important for me to go over there, face-to-face visit him in prison and tell him that that's not going to happen."

Erdogan has reportedly offered a trade of Brunson for Gülen, whom he blamed for the coup attempt. Tillis said such a deal was "absurd."

• Trump Calls for Turkey to Release Pastor Andrew Brunson
• US Pastor Denies Terror Links, Spying in Turkish Court