"‘Deterrence’ was what they were planning for,” said a former senior Homeland Security adviser who reviewed the document.

Rebecca Blackwell / AP Migrants are escorted by a US Border Patrol agent as they are detained in San Ysidro, California.

WASHINGTON — In the early months of the Trump administration, senior officials examined the effects of plans to deter immigration at the southern border by separating families and tracking down those undocumented individuals who came forward to pick up unaccompanied children at government shelters, according to a document obtained by BuzzFeed News.

The document, which was part of the House Judiciary Committee’s ongoing requests from the Trump administration on family separation, sheds further light on the administration’s focus since its earliest days on implementing various policies to deter immigration at the southwestern border.

In a memo dated July 4, 2017, Jonathan White, the former deputy director of the Office of Refugee Resettlement, which oversees unaccompanied minors, laid out how Immigration and Customs Enforcement efforts to track down certain sponsors — those who pick up unaccompanied children in government facilities — will likely lead to “significant increases in length of stay and decline in discharge rate.” White appeared to be referencing operations conducted by ICE in 2017 in which agents targeted undocumented sponsors of children in facilities to fight what they described as smuggling of children into the country. White wrote that such a result would “represent” one-half of the policy changes necessary to fulfill the “‘DHS Deterrence’ scenario model (since family unit separations are not yet being implemented).” That scenario, he said, would lead to a need for more housing for migrant children.

Jose Luis Magana / AP Jonathan White testifies before the House Judiciary Committee in February.

White explained that his office was reviewing whether to alter the model given the policy realities at the time.

Scott Shuchart, a former senior Department of Homeland Security adviser who reviewed the document, said that it appeared the memo was a model for policies that the agency and White House wanted.

“‘Deterrence’ was what they were planning for,” he said. Aaron Reichlin-Melnick, a policy analyst at the American Immigration Council, said the memo confirms government officials tasked with planning for family separation knew it was about deterrence. The memo came just a few months after then–DHS secretary John Kelly said on CNN that his administration was considering separating families as a deterrent to migration. He later walked back the comments. Homeland Security Secretary Kirstjen Nielsen has long said that the administration's “zero tolerance” policy, which led to increased prosecutions of those who crossed the border without authorization, was different from a policy that would actively separate parents as a deterrent. The zero tolerance policy led to family separations after parents were transferred into criminal custody, where children could not be placed. In a December 2017 memo laying out immigration policies, leaked by Sen. Jeff Merkley, an option to outright separate families at the border was listed after the option to increase prosecutions at the border, which was later enforced. During a hearing in front of the House Homeland Security Committee, Nielsen reiterated this stance, stating that there was no policy of family separation but rather a policy to refer more parents for prosecution and that it was not a policy to deter more migration.

Jim Watson / AFP / Getty Images Homeland Security Secretary Kirstjen Nielsen