New Jersey Gov. Chris Christie wants the Port Authority of New York and New Jersey to reject an effort to open flight service between Newark and Cuba until a woman convicted of killing a state trooper is returned to the United States.

Chicago-based United Airlines has expressed interest in starting the flight but has not requested it.

Christie says in a letter to Port Authority Chairman John Degnan obtained by The Associated Press flight service to Cuba is an “unacceptable” prospect until Joanne Chesimard is extradited. Chesimard was convicted in 1977 but escaped to Cuba and has been living there since.

President Barack Obama announced plans to normalize relations with Cuba last year.

Christie is running for the Republican nomination for president and has repeatedly criticized the changes.

(AP)