China is unhappy with the move by US President Donald Trump's move to declare the country among the world's worst human trafficking offenders.

Foreign ministry spokesman, Lu Kang said Tuesday that China strongly opposes the U.S. using its domestic laws to attack another country's record, and maintained that the results of China's anti-human trafficking efforts are "obvious for everyone to see."

The U.S. State Department is expected to unveil later Tuesday a new human trafficking report that downgrades China to the lowest "Tier 3" category, which includes North Korea, Zimbabwe and Syria.

Tier 3 countries can be penalized with sanctions or barred from participating in U.S. cultural exchange programs, although the U.S. president has the authority to waive sanctions.