Assistant Secretary of State for Human Rights, Democracy and Labor Tom Malinowski led a U.S. delegation that met in Beijing with government representatives to discuss legal issues.
He said there was no question that Chinese laws "have been thrown by the wayside" in the detentions of rights lawyers and others.
The detentions appear to be part of moves to snuff out any potential groundswell of opposition to the Communist Party.
Chinese officials have said such cases are being handled according to law, and that no other country should interfere. The U.S.-China Legal Experts Dialogue took place Thursday and Friday.