Jacqueline Furnari, Brunson’s daughter, told NBC News her family is happy the case is moving forward but is concerned it could drag on further.

“I’m not sure exactly why my dad was chosen,” she said. “He’s a pawn in a political game between Turkey and the U.S.”

Furnari, who has not seen her father since last August, says Brunson’s mood is improving and he is gaining back some of the 50 pounds he lost while in detention.

“The start was very, very difficult. It was a dark time,” she said. “This week he’s anxious… but altogether he’s doing a lot better.”

She added, “He’s done nothing wrong, he’s a peaceful loving man, he’s a pastor. These charges are absolutely absurd.”

Brunson was arrested during the mass detentions and firings soon after a failed July 2016 coup attempt, initially on immigration violation charges.

He’s now charged with connections to the Kurdistan Workers Party (PKK), a Kurdish militant group which Turkey and the United States deem a terrorist organization, as well as links with the network of U.S.-based cleric Fethullah Gulen, who Ankara blames for carrying out the coup attempt.

The indictment also charges Brunson with revealing state secrets, alleging that he communicated with people who gathered details about gas and railway stations, information which would have strategic importance during a war or occupation.

The indictment states the charges are based on evidence obtained from Brunson’s phone, as well as from witnesses given pseudonyms to mask their identity.

The pastor’s lawyer, Ismail Cem Halavurt, told NBC News that he’s not been told who the witnesses are and that Brunson denies the charges.

He denies any wrongdoing, and the United States has repeatedly demanded his release.

In March, then-Secretary of State Rex Tillerson met with Brunson’s wife during a trip to Turkey to visit President Recep Tayyip Erdogan.

A senior U.S. official told NBC News, “We are following this case closely, and since his arrest, we have visited Mr. Brunson regularly. We believe that Turkey is a state of law, and we have faith in the Turkish people’s commitment to justice.”

Ambassador-at-Large for International Religious Freedom Sam Brownback has been to Turkey and Republican Sen. Thom Tillis of North Carolina is expected to attend the trial at some point.

After visiting Brunson in prison in March, Tillis stated that “Pastor Brunson is being used as a political pawn by some elements of the Turkish government.”

Last September, Erdogan said that Turkey would send Brunson back to the United States if Washington carried out an extradition request for Gulen.

“Give him (Gulen) to us,” Erdogan said. “Then we will try him (Brunson) and give him to you.”

Washington said it did not receive sufficient evidence showing Gulen’s connection to the coup attempt.

Halavurt said that while Brunson was physically fine, he was anxious for his day in court.

Halavurt said he expects his client to be released on Monday over what he called “very weak” accusations, but added that recent cases have shown that may not happen.

“This is a special, delicate trial and if we look at other trials that have been held in this last period, we see that some people have been condemned without enough evidence, so it’s a risk we have to consider.”

Since the failed coup, Turkey has jailed over 50,000 people including journalists, academics and judges. The purges have led to widespread criticism of the country’s authoritarian president.

Soner Tufan, a spokesperson of the Association of Protestant Churches who had attended Brunson’s church, said Brunson was not connected to any political organizations.

“He’s not guilty, he’s not a spy, he’s not working for CIA or other kind of organization,” Tufan said. “He’s just a [pastor].”

Multiple other U.S. citizens are being detained in Turkey, including NASA scientist Serkan Golge, who was sentenced to over seven years in prison on terrorism charges.

The State Department said it was deeply concerned by the conviction.

Relations with Turkey were strained further recently after it launched an offensive in northern Syria in January against the Kurdish YPG militia, which is allied with the United States.

Turkey is a crucial ally to the United States in the region, hosting an air base which NATO has used for strikes against the so-called Islamic State in Syria.