President Donald Trump on Sunday blamed Democrats for his own administration’s policy of separating undocumented immigrant children from their parents when they are arrested at the border.

Put pressure on the Democrats to end the horrible law that separates children from there parents once they cross the Border into the U.S. Catch and Release, Lottery and Chain must also go with it and we MUST continue building the WALL! DEMOCRATS ARE PROTECTING MS-13 THUGS. — Donald J. Trump (@realDonaldTrump) May 26, 2018

In fact, it was Attorney General Jeff Sessions who flagged the policy in a speech earlier this month, when he pledged to criminally prosecute as many illegal border crossing cases “as humanly possible.”

“If you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law,” Sessions said. “If you don’t like that, then don’t smuggle children over our border.”

Homeland Security Secretary Kirstjen Nielsen used similar language in congressional testimony a week later.

“Our policy is if you break the law, we will prosecute you,” Nielsen said. “You have an option to go to a port of entry and not illegally cross into our country.”

By prosecuting undocumented immigrants criminally, rather than processing their cases through civil immigration courts, the Trump administration has ensured that the many children of such criminally-charged migrants would technically become unaccompanied minors and would be put in the care of the Department of Health and Human Services.

The announced change to formal policy came after months of examples of migrant families being separated.

HHS admitted last month that nearly 1,500 unaccompanied minors were unable to be accounted for during a recent survey.

And a recent report from the ACLU and the University of Chicago Law School’s International Human Rights Clinic, the result of years of litigation over a request for government documents, detailed hundreds of cases of alleged physical and emotional abuse made by unaccompanied minors during the Obama administration against U.S. Customs and Border Protection. CBP called the reports claims “unfounded and baseless.”