The United States designated North Korea as one of the world's worst countries for human trafficking for the 14th straight year on Thursday, saying the communist nation subjects its people to forced labor at home and abroad.

The State Department's annual "Trafficking in Persons Report 2016" put North Korea in the lowest Tier 3 of its four-step classification of countries. The North has been classified in the lowest category since the annual report began including it in 2003.

"The government subjects its nationals to forced labor through mass mobilizations and in North Korean prison camps. Many North Korean government-contracted laborers in foreign countries also face conditions of forced labor," the report said.

The North holds an estimated 80,000 to 120,000 prisoners in political prison camps in remote areas of the country, the report said, adding that in many cases, these prisoners have not been charged with a crime or prosecuted, convicted, or sentenced in a fair, judicial hearing.

On labor exports, which has increasingly become a source of hard currency for the regime, the report said that credible reports show many such workers are subjected to conditions indicative of forced labor, such as working excessively long hours in hazardous temperatures with restricted pay, for up to three years.

"The government of North Korea does not fully meet the minimum standards for the elimination of trafficking and is not making significant efforts to do so. The government did not demonstrate any efforts to address human trafficking through prosecution, protection, or prevention measures," the report said.

"The government participated in human trafficking through its use of forced labor in prison camps and labor training centers, and its provision of forced labor to foreign governments through bilateral contracts. It failed to protect trafficking victims when they were forcibly repatriated from China or other countries," it said.

Other Tier 3 countries include Iran, Russia, Sudan and Syria.

The report put South Korea among Tier 1 countries, along with other advanced countries like the U.S., Britain, France and Germany.

It put Japan in Tier 2, saying the country is a destination, source and transit country for men and women subjected to forced labor and sex trafficking as well as for children subjected to sex trafficking. (Yonhap)