A court in Vladivostok, Russia, has commenced the trial of US Army Staff Sergeant Gordon Black, 34, who was arrested earlier this year on charges of theft and threatening to kill his girlfriend. Black traveled to Vladivostok to visit his girlfriend, Alexandra Vashchuk, when she accused him of stealing 10,000 roubles ($110) and making threats after a domestic dispute. Black was detained on May 2 and faces up to five years in prison if convicted.

The Pentagon confirmed that Black traveled to Russia without authorization, having passed through China. He was stationed at Camp Humphreys in South Korea with the Eighth Army before his move back to Fort Cavazos, Texas. The US Army revealed that Black did not seek the necessary travel clearance for his trip.

The trial at Pervomaisky District Court includes testimonies from both Black and Vashchuk. Black has admitted to his guilt regarding the theft but has yet to enter a plea concerning the threat charges. The situation adds tension to already strained US-Russia relations.

The US State Department warns American citizens against traveling to Russia, citing potential harassment and arbitrary detention by Russian authorities. Black’s case joins a list of other detained Americans in Russia, including Paul Whelan, Evan Gershkovich, and Marc Fogel.