MOSCOW, June 16 (RIA Novosti) - North Korea has said that the two U.S. journalists sentenced last week to a labor camp have admitted to shooting a "smear" video on human rights in the country, the Yonhap news agency reported.

Laura Ling and Euna Lee were sentenced on Monday to 12 years of hard labor for illegally crossing the border from China in March while working on a story for San Fransisco-based Current TV.

"At the trial, the accused admitted that what they did were criminal acts...prompted by the political motive to isolate and stifle the socialist system of the DPRK (North Korea) by faking moving images aimed at falsifying its human rights performance," the agency said, quoting the Korean Central News Agency.

The families of Lee and Ling issued a joint statement last Monday asking North Korea to "show compassion and grant Laura and Euna clemency, and allow them to return home to their families."

"We don't know what really happened on March 17, but if they wandered across the border without permission, we apologize on their behalf and we are certain that they have also apologized," the statement said.

CNN quoted senior U.S. administration officials as saying that either former vice president Al Gore, who founded Current TV, or New Mexico Governor Bill Richardson, could be sent to Pyongyang to negotiate the journalists' release.