Several top immigration and border officials are pressuring Department of Homeland Security (DHS) Secretary Kirstjen Nielsen to prosecute immigrant parents caught crossing the United States-Mexico border with their children. It’s a policy shift that would result in thousands of families being separated, The Washington Posts reports.

In a memo viewed by The Post, officials say that border crossings could rise if DHS does not act, and that threatening parents with prison would be the “most effective” way to decrease crossings.

While border crossings rose in March, according to U.S. Customs and Border Protection figures, they remain modest compared to previous years and reached a 46-year low in 2017. 

The memo, signed by Immigration and Customs Enforcement director Thomas Homan and Border Protection commissioner Kevin McAleenan, says attempted border crossings by parents and their children rose last week to almost 700 a day, a level not seen since 2016. 

In a statement to The Post, DHS spokesperson Katie Waldman said the agency “is looking at all options in conjunction with the attorney general’s zero tolerance policy for those illegally crossing the border. We will not comment further on internal deliberations.”

President Donald Trump has vowed to end the practice of releasing immigrants of undocumented status while they await immigration hearings. And although the administration has freed a majority of parents stopped at the border, that policy could be changing.

According to data viewed by The New York Times, more than 700 children have been separated from their parents since October, including hundreds of children under age 4. In February, the New York Civil Liberties Union (NYCLU) sued the Office of Refugee Resettlement, which takes custody of children separated from their parents, for what it called the “restrictive imprisonment” of prolonged detention of immigrant children. 

“The Trump administration is trapping children, many of whom came to New York to escape trauma and violence, in purgatory, separating them from their families and upending their lives,” Donna Lieberman, executive director of the NYCLU, said in a statement.

On Thursday (April 26), as hundreds of Central American migrants crossing Mexico prepared to enter the U.S., secretary Nielsen warned that members of the “caravan” would be prosecuted.

“Individuals of the ‘caravan’ seeking asylum or other similar claims should seek protections in the first safe country they enter, including Mexico,” Nielsen said in a statement. “The smugglers, traffickers and criminals understand our legal loopholes better than Congress and are effectively exploiting them to their advantage.”