US seeks release of Otto Warmbier, says Pyongyang uses its citizens as pawns

The 21-year-old student at the University of Virginia was also accused of committing hostile acts.

The US has asked North Korea to release immediately student Otto Warmbier, who was sentenced to 15 years of hard labour, saying Pyongyang is using US citizens as "pawns to pursue a political agenda".

"We strongly encourage the North Korean government to pardon him and grant him special amnesty and immediate release," White House spokesman Josh Earnest 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," the spokesman added.

Otto Warmbier was arrested in January and charged with trying to steal a propaganda sign from a hotel.

The 21-year-old student at the University of Virginia was also accused of committing hostile acts. The char sheet said he took down a political slogan from the staff holding area of the Yanggakdo International Hotel.

North Korea says the student was manipulated by the US government. Later, the student appeared on state TV, making an apparent confession on those lines.

"The aim of my task was to harm the motivation and work ethic of the Korean people. This was a very foolish aim," he said on air adding that it was the worst mistake of his life.

The US routinely advises its citizens against travel to North Korea saying they risk being arrested in the reclusive communist country.

The student's sentencing came even as US was trying to push for his release through a meeting with Pyongyang's diplomats in New York.

Washington has no direct diplomatic ties with Pyongyang. Limited diplomatic assistance is provided to US citizens in North Korea trough the Swedish embassy in Pyongyang.

Meanwhile, the Human Rights watch said the student's act which attracted the sentencing was no more than a college prank.

"Pyongyang should recognise this student's self-admitted mistake as a misdemeanour ... release him on humanitarian grounds, and send him home," said Phil Robertson, HRW's deputy director.