Foreign Ministry spokeswoman Jiang Yu Thursday made it clear Beijing considers the case of Liu Xiaobo no one else's business.

Jiang says that Liu Xiaobo is a Chinese citizen and his case is being handled by judicial authorities according to Chinese law. 

Liu has been in police custody for more than one year. He was among a group of dissidents who wrote "Charter 08", a document calling for greater respect for human rights and democratic reform. Thousands of Chinese citizens have signed the on-line document.

He is being charged with subversion and could be sentenced to as many as 15 years in prison.

Foreign diplomats were among the people gathered outside of the courthouse during Liu's trial Wednesday. Court officials said the trial was open, but that the diplomats could not attend because all of the passes had already been distributed.

The U.S. State Department Wednesday criticized the proceedings as a "political trial" that will likely lead to a "political conviction." Strong statements were also issued by the U.S. embassy and European Union offices in Beijing.

The Chinese spokeswoman expressed her country's strong dissatisfaction with the criticism.

Jiang says these statements are, in her words, "gross intrusions into China's judicial affairs." She says they also violate international conventions on diplomatic relations.

She says China urges critical countries to respect its judicial sovereignty and to stop interfering in its internal affairs.

The verdict for Liu Xiaobo is expected Friday.