China has rejected a U.N. refugee agency request not to send some North Koreans back to their starving homeland.
China's Foreign Ministry spokeswoman Zhang Qiyue says 78 detained North Koreans are not refugees entitled to special protection and help.
Ms. Zhang says they are instead illegal economic migrants looking for work and should be sent back to North Korea as soon as possible.
She also confirmed that two South Koreans are being held in "criminal detention" and are suspected of smuggling a number of North Koreans into China.
Tuesday, the U.N. refugee agency pleaded with Beijing not to send the asylum-seekers back to North Korea.
Aid groups say China has shipped thousands of North Koreans back across the border in recent weeks. Activists who help the asylum-seekers say North Koreans returned home might face imprisonment or torture.
China says it handles these cases "according to international and Chinese law, in a humanitarian fashion."
Up to 300,000 North Korean migrants are thought to be hiding in northeastern China near the border with North Korea, driven out of their homeland by hunger and political oppression.
More than 100 of these migrants have come to international attention in the past year by scrambling into embassies in Beijing and demanding political asylum in South Korea. China eventually permits such migrants to leave via a third country to avoid angering its ally, North Korea.
Human rights groups and U.N. officials say there is a growing humanitarian crisis under way in the isolated communist state.