BEIJING — A senior official from China’s far west said on Tuesday that the internment camps for Muslim minorities there were like boarding schools and that their numbers of inmates would shrink, as the government pushed back against international criticism of the mass detentions.

China’s sweeping confinement of Uighurs and other Muslim minorities in the Xinjiang region has drawn condemnation from foreign governments and international bodies, including in recent weeks. A United States envoy called it part of a “war with faith.” Turkey, once quiet about the detentions, has become critical. The United Nations high commissioner for human rights recently demanded answers.

[Update: Leaked documents show China’s Internment Camps Ruled by Secrecy and Spying.]

Yet at the annual meeting of China’s national legislature, which began last month, Communist Party officials from Xinjiang appeared serenely unbowed about the policies.

Foreign experts, citing satellite images and government documents, have estimated that the camps have held without trial as many as a million Uighurs, Kazakhs and other Muslims in a program that tries to turn them into loyal, Chinese-speaking supporters of the party.