SEOUL (Reuters) -A U.S. national is likely to be in North Korean custody after crossing the inter-Korean border during a tour without approval, the U.N. Command said on Tuesday.

The person was taking part in a tour to the Joint Security Area, the border village in the demilitarised zone separating the two Koreas where soldiers from both sides stand guard.

"A U.S. National on a JSA orientation tour crossed, without authorization, the Military Demarcation Line into the Democratic People's Republic of Korea (DPRK)," the U.N. Command said on Twitter.

"We believe he is currently in DPRK custody and are working with our KPA counterparts to resolve this incident," it added, referring to North Korea's People's Army.

(Reporting by Hyonhee Shin and Soo-hyang Choi; Editing by Andrew Heavens and Tomasz Janowski)