The Trump administration has declared China one of the worst human trafficking offenders in the world.

FOX's Rachel Sutherland reports from Washington:

Secretary of State Rex Tillerson says a new report on human trafficking shows tens of thousands of people are forced to work 20 hours a day in China, and that the U.S. has downgraded the nation to "tier 3", the lowest level, alongside North Korea and Syria:

(Tillerson) "It has not taken serious steps to end its own complicity in trafficking."

China's foreign ministry has said it strongly opposes the U.S. using its domestic laws to attack another country's record.

In Washington, Rachel Sutherland, FOX News.

Follow Rachel Sutherland on Twitter: @SutherlandFOX