The United States lists North Korea, Burma and Malaysia as among the worst offenders in its annual human trafficking report.
In the report released today by the U.S. State Department, it raised concerns that North Koreans sent overseas to work are subject to harsh conditions.
Also on North Korea, the report says that women and children are promised jobs outside the country and then are forced into labor and are sexually exploited.
On Burma, the report says women, men and children are trafficked to several countries including Thailand and China for the purpose of forced labor and sexual exploitation.
Malaysia made the "worst offenders" category for the first time this year. The report said Malaysia is a transit country for women and children trafficked for sexual exploitation.
In the report's "tier two" category -- one level up from the worst offenders, it lists East Timor, Indonesia, Singapore, Thailand, Vietnam and Taiwan.