A government spokesman rejected Cambodia's status in the US State Department's "Trafficking in Persons" 2007 report, issued Tuesday, which held the country on a watch list for failing to do enough to combat the crime.
Spokesman Khieu Kanharith said the report was unfounded and unfair.
The annual report is the US's top diplomatic tool to pressure countries to fight what the State Department deems "modern-day slavery."
The report acknowledged the Ministry of Interior's Anti-Trafficking Police Unit for initiatives to educate school children on their rights and the risks of trafficking, but other efforts had fallen short of the requirement to move Cambodia to Tier 2, a list of countries that are making sufficient efforts to curb trafficking.
"Cambodia is placed on Tier 2 Watch List for the second consecutive year because it failed to show evidence of increasing efforts to combat trafficking in persons, particularly in addressing reports of public officials' complicity in trafficking," the report said.
Cambodia also has failed to pass an anti-trafficking law that has been in the drafting stage for seven years, the report said.