Concerning the detention camps the US uses to warehouse tens of thousands of refugees, including children, one expert said: “We have what I would call a concentration camp system & the definition of that in my book is, mass detention of civilians without trial.”
Another expert on concentration camps said, “Things can be concentration camps without being Dachau or Auschwitz.”

https://www.esquire.com/news-politics/a27813648/concentration-camps-southern-border-migrant-detention-facilities-trump/?