Systemic deportation is a crime against humanity.

According to the Rome Statute, there are eleven types of crimes that can be charged as a crime against humanity when "committed as part of a widespread or systematic attack directed against any civilian population": "murder; extermination; enslavement; deportation or forcible transfer of population; imprisonment or other severe deprivation of physical liberty in violation of fundamental rules of international law; torture; rape, sexual slavery, enforced prostitution, forced pregnancy, forced abortion, enforced sterilization, or any other form of sexual violence of comparable gravity; persecution against any identifiable group or collectivity...; enforced disappearance...; the crime of apartheid; other inhumane acts of a similar character intentionally causing great suffering, or serious injury to body or to mental or physical health."

https://en.wikipedia.org/wiki/Crimes_against_humanity