The soldier, who was stationed in South Korea, traveled to Russia on his own to visit a woman he was romantically involved with, officials said.

A U.S. soldier was detained in Russia last week, a U.S. Army spokesperson said in a statement.

The soldier, Staff Sgt. Gordon Black, had been stationed in South Korea and traveled to Russia on his own, not on official business, according to four U.S. officials.

He had finished his deployment and was heading back to the U.S. when he made a side trip to Vladivostok, Russia, to visit a woman he was romantically involved with, officials said. They added that he had traveled there without permission from his superiors and that he is being held in pretrial confinement.

The soldier is accused of stealing from a woman, the officials said. It was not immediately clear whether it was the same woman he was visiting.