A court in Shenzhen this week sentenced Wang, also known as Wang Jianmin, to five years in prison on charges of running an illegal business, bribery and collusion after he sent copies of his sensitive political magazine to mainland China.
State Department spokesman John Kirby said the US was not permitted to attend Wang's trial and will continue to request visits.
Wang's lawyer Chen Nansha said today that Wang might not appeal the verdict. Wang also holds residency in Hong Kong a semiautonomous Chinese territory and last entered China with his Hong Kong identity card before his arrest, Chen said.
Wang, along with editor Guo Zhongxiao, who was also arrested in mainland China in 2014, published New Way Monthly and Faces, two journals that often delved into high-level Communist Party intrigue.
Their arrests and convictions, following the temporary disappearance of five Hong Kong booksellers, has raised questions about Hong Kong's status as a free press haven and has cast a chill over the territory's free-wheeling political book trade.