From the AP, via Chron.com (link);
China is refusing to take back an estimated 39,000 citizens who have been denied immigration to the United States and have clogged detention centers at federal expense, Homeland Security Secretary Michael Chertoff said Tuesday.
In an interview with The Associated Press, Chertoff said that China last year readmitted 800 people. But that made only a small dent in what he described as a backlog of thousands illegally in the U.S.
"The math is pretty easy _ at that rate, we wind up with increasing numbers of migrants who, if we're going to detain them, we're going to have to house at enormous expense," Chertoff said.