A US tourist crossed the border into North Korea, UN says. South Korean media reports he's a US soldier.

• A US national crossed the border from South Korea into North Korea on Tuesday, the UN said.
• South Korean media is reporting that he was a US soldier. It is unclear if this was a defection. 
• The man is currently believed to be held in North Korean custody, the UN said.

A US tourist crossed the heavily fortified border from South Korea to North Korea on Tuesday, according to the United Nations.