President Trump said Monday that the U.S. will not become “a migrant camp,” as his administration continues to face backlash over a zero tolerance immigration policy that has caused thousands of children to be separated from their parents at the southwest border.

“The United States will not become a migrant camp and it will not be a refugee holding facility. Won’t be,” the president told White House aides at an event on space policy. “You look at what’s happening in Europe, you look at what’s happening in other places. We can’t allow that to happen in the United States.”