These undated photo show American journalists Laura Ling (right) and Euna Lee.

North Korea's state news agency says a court has sentenced two female American journalists to 12 years of hard labor. The Korean Central News Agency said Monday that the court found the two women guilty of committing an unspecified "grave crime" and illegally crossing into North Korea.

Last Thursday, North Korean state media announced the start of the trial of Euna Lee and Laura Ling, reporters for the U.S. media company Current TV.

North Korean authorities arrested Lee and Ling in March while they were working on a story near the Chinese-North Korean border. U.S. State Department spokesman Ian Kelly said Monday the United States is deeply concerned by the reported sentencing and is engaged through all possible channels to secure the journalists' release. Last week, before the trial began, relatives and supporters of Lee and Ling held candlelight vigils in several U.S. cities and pleaded for leniency.

Since their arrests, political analysts have speculated that North Korea may use the pair as a diplomatic bargaining chip in disputes with the United States.

The administration of U.S. President Barack Obama has dismissed the charges against the reporters as "baseless."

Some information for this report was provided by AFP, AP and Reuters.