WASHINGTON – Homeland Security Secretary Kirstjen Nielsen is considering a series of measures to halt a new surge of Central American families and unaccompanied minors coming across the Mexican border, including a proposal to separate parents from their children, according to Trump administration officials with knowledge of the plans.

These measures, described on condition of anonymity because they have not been publicly disclosed, would also crack down on migrants already living in the U.S. illegally who send for their children.

That aspect of the effort would use data collected by the Department of Health and Human Services (HHS) to target parents for deportation after they attempt to regain custody of their children from government shelters.

The Department of Homeland Security (DHS) has previously considered some of these proposals, but there is renewed urgency within the administration to address an abrupt reversal of what had been a sharp decline in illegal immigration since Donald Trump took office in January.

In November, U.S. agents took into custody 7,018 families, or “family units,” along the border with Mexico, a 45 percent increase over the previous month, the latest DHS statistics show. The number of Unaccompanied Alien Children, or UACs, was up 26 percent.

Children’s shelters operated by HHS are now at maximum capacity or “dangerously close to it,” an official from the agency said. Overall, the number of migrants detained last month along the Mexico border, 39,006, was the highest monthly total since Trump became president, according to DHS figures.

The proposals were developed by career officials at Immigration and Customs Enforcement (ICE) and other DHS agencies, administration officials said.

Tyler Houlton, a DHS spokesman, confirmed the agency has “reviewed procedural, policy, regulatory and legislative changes” to deter migrants.

Without giving further details, he said some of the measures “have been approved,” and DHS is working with other federal agencies “to implement them in the near future.”

“The administration is committed to using all legal tools at its disposal to secure our nation’s borders, and as a result we are continuing to review additional policy options,” Houlton said.

The most contentious proposal — to separate families in detention — would keep adults in federal custody while sending their children to HHS shelters. This was floated in March by then-Secretary of Homeland Security John Kelly, now the White House chief of staff. He told CNN at the time that the children would be “well cared for as we deal with their parents.”

Kelly did not move forward with the plan, in part because of the backlash it triggered, administration officials said, and also because illegal migration had plunged to historic lows.

Trump administration officials described the measures as an unpalatable but necessarily tough series of policy options to discourage Central American families from embarking on the long, dangerous journey to the border or hiring smugglers to bring their kids north.

“People aren’t going to stop coming unless there are consequences to illegal entry,” one DHS official said.