North Korea has the world's worst human trafficking record and is not making any tangible efforts to improve the situation, according to the United States.
In its categorization of nations in terms of their commitment to observing and improving human rights, the State Department has kept the reclusive nation at Tier 3 for the 12th consecutive year since 2003.
In contrast, South Korea remained at Tier 1 in recognition of its efforts to abide by the Trafficking Victims Protection Act. Tier 3 is comprised of countries with governments that do not fully comply with the act and make little effort to do so.
The North has failed to keep the minimum standards of the act, the department says in the 2014 Trafficking in Persons Report.
"The Democratic People's Republic of Korea (DPRK) is a source country for men, women, and children who are subjected to forced labor and sex trafficking," according to the report, which was released on Friday.
It criticizes North Korea for having about 80,000 to 120,000 prisoners in political concentration camps in remote areas without filing formal criminal charges against them in accordance with fair legal process.
The report says the North's system of harsh punishment, including the death penalty and forced labor, can have a far-reaching impact on neighboring countries like China, prompting human trafficking there.
Given this background, North Korean defectors crossing the border with China have been vulnerable to such trafficking with many women being kidnapped for sexual slavery, for instance, the report says.
"If caught by the Chinese authorities, they are supposed to be repatriated to the North where they face severe punishment of being put into concentration camps for forced labor or the death penalty," it adds.
The report also includes 22 other countries in the group of Tier 3, including Iran, Russia and Zimbabwe. China has moved from Tier to Tier 2. China still has many problems, but has made "significant efforts" to improve the human rights situation, it notes.
But House Foreign Affairs Committee chairman Ed Royce (R-CA), disapproves of China's upgrade, taking issue with China's practice of sending North Korean defectors back to the country.
"We know that the system of state-sponsored forced labor continues unchanged and that victims of trafficking from North Korea are routinely sent back to face further abuses," he said.
Secretary of State John Kerry cited the need for the world to make further concerted efforts to cope with the human trafficking, describing it vital and challenging.
"The United States is engaged on countless active fronts on every continent across the globe ― big, simultaneous confrontations and efforts," he said in a statement. He said this year's Trafficking in Persons Report offered a roadmap for the future.