SEOUL  Two American journalists detained in North Korea will be indicted and tried on charges of perpetrating "hostile acts" against the Communist state, a crime punishable by years in a labor camp, the North’s state-run news agency reported on Tuesday.

Pyongyang’s decision to put Laura Ling and Euna Lee on trial signaled that the regime has no intention of freeing them soon.

Their indictment comes amid heightening tension between Pyongyang and Washington over a North Korean plan to launch a rocket by Wednesday next week. United States officials consider a possible rocket launch a provocative test of the North’s long-range missile technology.

Ms. Ling and Ms. Lee, reporters for Current TV, a San Francisco-based media venture founded by former U.S. Vice President Al Gore, were arrested by the North Korean military on March 17 on charges of illegally crossing the border from China. They were in China to report the plight of North Korean refugees who fled hunger at home and were living in hiding there.