GENEVA -- The human rights situation in North Korea is "deplorable," with some 200,000 people held in political prison camps and subjected to torture, rape and slave labour, the top UN human rights official said Monday.

UN High Commissioner for Human Rights Navi Pillay's stinging criticism comes a year after Kim Jong Un became North Korea's new leader, after the death of his father.

"There were some initial hopes that the advent of a new leader might bring about some positive change in the human rights situation," Pillay said in a statement. "But a year after Kim Jong Un became the country's new supreme leader, we see almost no sign of improvement."

Pillay said nations must mount "a full-fledged international inquiry into serious crimes" such as a network of political prison camps that she said are believed to hold 200,000 or more people.

While the world's focus is on North Korea's nuclear program and its rocket launches, Pillay said, those important issues "should not be allowed to overshadow the deplorable human rights situation ... which in one way or another affects almost the entire population and has no parallel anywhere else in the world."

Pillay said North Korea has also used the death penalty to punish minor offences and it has abducted South Korean and Japanese nationals over the years.

North Korea's mission to the United Nations in Geneva, who was given a copy of the report before its publication Monday, did not have an immediate public response to it.