The Trump adviser who pushed a plan to separate migrant children from their families now says that President Joe Biden deserves the "eternal shame of history" over his border policies.

During an interview on Fox News, former Trump adviser Stephen Miller blasted Biden for dismantling Trump-era immigration policies.

"The decision to terminate President Trump's hugely successful border controls is a crime against humanity," Miller told Fox News host Maria Bartiromo. "And my plea to every single member of Congress on the Republican side of the aisle is raise holy hell about what's happening on our border."

He added: "This administration deserves to lose not only a record number of seats in the House and the Senate over this border crisis but the eternal shame of history! For what they have done has no precedent. It is an abomination."

During his time in the White House, Miller pursued harsh immigration policies that separated children from their families. Activists have called for the International Criminal Court to charge Miller with crimes against humanity for his role.