The Trump administration will end the Deferred Action for Childhood Arrivals program, the Obama-era directive that provided work permits and protection from deportation for illegal immigrants brought to the country as children, after a six-month window, Attorney General Jeff Sessions announced Tuesday.

Speaking to reporters Tuesday morning, Sessions blasted DACA as a “unilateral executive amnesty” and an “unconstitutional exercise of authority” by the Obama administration. Obama created the program through executive order in 2012.