SEOUL • The United States accused North Korea on Wednesday of jailing an American student for political reasons, and called for his immediate release after Pyongyang sentenced him to 15 years' hard labour under a criminal code dealing with subversion for stealing a propaganda sign from a hotel.

Otto Warmbier, a 21-year-old student from the University of Virginia, was convicted of subversive activities and sentenced by North Korea's Supreme Court, the North's official Korean Central News Agency (KCNA) said.

White House spokesman Josh Earnest charged that North Korea was using US citizens as "pawns to pursue a political agenda" and urged it to free him. "We strongly encourage the North Korean government to pardon him and grant him special amnesty and immediate release," he said. "The allegations for which this individual was arrested and imprisoned would not give rise to arrest or imprisonment in the United States or in just about any other country in the world."

Observers said the sentence was likely a reflection of soaring military tensions on the divided Korean peninsula following the North's nuclear test in January and long-range rocket launch a month later. The US took a leading role in securing the resulting sanctions that the United Nations Security Council imposed on the North earlier this month.

KCNA said Warmbier had committed his offence "pursuant to the US government's hostile policy".

The youth had been arrested in early January as he was leaving the country with a tour group. He had removed a political banner from the hotel where the group had stayed.

Warmbier is one of three North Americans detained in North Korea now. Recently a 60-year-old Canadian pastor was sentenced to life imprisonment with hard labour on sedition charges.

AGENCE FRANCE-PRESSE