A Chinese man has pleaded guilty in eastern China to killing his girlfriend in the United States where the pair were students in the state of Iowa, a court officer said Thursday.

Li Xiangnan entered the plea to murder during a daylong hearing Wednesday, said an officer in charge of trial documents at the Intermediate People's Court in the city of Wenzhou. The officer refused to give her name, citing court regulations.

Li, a former University of Iowa student, surrendered to police in Wenzhou last May after returning to China following the slaying of his girlfriend, 20-year-old Chinese national Shao Tong, who was a student at Iowa State University. Her body was found stuffed into the trunk of her car in September 2014.

China does not extradite its citizens and says it can put them on trial itself regardless of where a crime occurred.

The court officer said that prosecutors say Li planned the killing, but Li's lawyer argued the crime wasn't premeditated. The case would continue at an unspecified later date, the officer said.