The United Nations said that any forced displacement of people is tantamount to ethnic cleansing.
It comes as North Korean troops are in Russia fighting against Ukraine, according to Ukrainian and other military sources.
North Korean leader Kim Jong Un has held a security meeting following what Pyongyang says were incursions by South Korean drones across the border.
North Korea on Friday reported its first coronavirus (COVID-19) death a day after first acknowledging an outbreak of the virus.
North Korea last tested a ballistic missile in October. Tests with such missiles were prohibited by UN resolutions.
