A US tour operator is facing indictment in North Korea on charges that he tried to overthrow the government there, the North's official Korean Central News Agency said Saturday.

The announcement, about the tour operator, Kenneth Bae, an American born in South Korea, could complicate Washington's difficult diplomatic balancing act as it tries to hold a tough line with North Korea over its nuclear program while avoiding confrontations that could lead to an armed conflict.

Bae, from Washington state, traveled with a group of businessmen in November from Yanji, China, to the North Korean special economic zone of Rason, where he was arrested. The news report Saturday said that the North had already finished its investigation and that Bae had admitted his guilt to charges that could draw the death penalty.

South Korean human rights advocates have described Bae as a devout Christian who not only ran tours to North Korea, but was also interested in helping orphans in the communist country. They said security officials in the North may have been offended by pictures of orphans that Bae had taken and stored in his computer.

North Korea, a police state, has often used the plight of detained Americans as a bargaining chip in its dealings with Washington. Some were freed only after former American presidents travelled to the North. Bae is the sixth American detained by North Korea since 2009, but he is facing the gravest charges.