WASHINGTON (AP) — The United States is criticizing China's imprisonment of a media freedom activist who was sentenced to six years after the late addition of charges that his attorneys were not given a chance to defend against.

State Department spokeswoman Elizabeth Trudeau said on Monday the trial of Yang Maodong fell short of international standards. She called the "last-minute" addition of new charges against Yang disturbing and urged his release.

Trudeau said China cannot build rule of law when "it uses imprisonment as a tool to punish Chinese citizens' peaceful expression of their views."

However, the U.S. was encouraged by the move to allow 71-year old journalist Gao Yu to serve the remainder of her sentence outside of prison due to health issues. She had been convicted on a state secrets charge.