A documentary that follows the work of former U.S. Sen. George Mitchell, who served as U.S. special envoy to Northern Ireland, will be featured in this year’s Maine International Film Festival.

“The Negotiator” will be screened on July 16 as the centerpiece film for the festival, which started Friday and runs through July 20 in Waterville. The festival will feature more than 100 films, including 25 made in Maine.

The film follows Mitchell’s political career and his work to broker the Good Friday Agreement in 1998 that ended decades of conflict in Northern Ireland. The documentary’s title is inspired by Mitchell’s aptitude to negotiate, not just in Northern Ireland, but again in the Middle East years later, the director of the film, Trevor Birney, said.

Birney is a Northern Ireland native and close friend of Mitchell, 91, who was born and raised in Waterville. Working as a young journalist in Belfast during the 1990s, Birney caught Mitchell’s attention.

“One day, at my home in Belfast, the postman brought me a letter from George Mitchell to thank me for the contribution that myself and other members of the press had made during those very tense and what seemed like never-ending negotiations,” Birney told the Press Herald this month.

He said he knew Mitchell was unlike other politicians after receiving his letter.

“He was writing letters to the press,” Birney said, adding “this wasn’t something that British ministers who were administering the government in Northern Ireland at the time were even doing. … It really struck me.”

Twenty five years after the agreement was signed, Mitchell gave a speech at Queen’s University in Belfast to commemorate its lasting success. Birney, who said he was involved in the making of an earlier documentary about Mitchell, said the speech inspired him to pursue his film.

“It was a speech which made the hairs stand up on the back of my neck,” he said. “It was a speech that implored the people of Ireland to recommit themselves to the Good Friday Agreement and to peace.”

Following the speech, Birney and his film company, Fine Point Films, enlisted the help of Mitchell and his wife to tell the story of the former senator’s life. He said they spent days recounting stories, traveled to Bar Harbor and spent countless hours sifting through details.

Although the film focuses on Mitchell’s legacy, Birney said the former senator made it clear to him that he wants to be remembered for his time in Belfast. Birney recalled a night in Los Angeles, in the middle of the film’s creation, when he received a phone call from Mitchell.

Birney said Mitchell told him: “I appreciate that you want to focus on everything I did in the Senate and what I achieved for Maine, but it’s what I achieved in Northern Ireland that I really want to be remembered for.”

The documentary was picked to be the festival’s centerpiece film, which is chosen each year by a vetting committee. The decision to highlight Mitchell as the festival’s focal point had to do with his humble beginnings, said Mike Perreault, executive director of the Maine Film Center. 

“What was really exciting to us about ‘The Negotiator,’ in particular, was the fact that George Mitchell was born and grew up just steps away from the center where we’ll host the festival,” he said.

The film will be screened at the Waterville Opera House at 7 p.m. July 16. Tickets can be purchased on the festival’s website.