The United States has declined so far to classify Army Pfc. Travis King as a prisoner of war, despite his being taken into North Korean custody after he crossed into the country last month, four U.S. officials said.

The decision, which could mean King is not covered by the protections entitled to prisoners of war under the Geneva Convention, is highly sensitive for the U.S. military given its commitment to leave no soldier behind enemy lines.

How to classify the 23-year-old, who dashed across the heavily guarded border during a civilian tour of the Demilitarized Zone separating North and South Korea, has been an open question for the military.