Department of Homeland Security officials considered a secret White House plan to arrest thousands of undocumented migrant parents and children in coordinated raids across the U.S., but the idea was tabled due to a lack of resources, reported The Washington Post and The Associated Press.

The massive operation was intended to deter people from crossing the border into the U.S. from Mexico, according to the Post and AP, which cited several unnamed current and former Homeland Security officials.

But the proposal was reportedly challenged by then-DHS Secretary Kirstjen Nielsen and then-Immigration and Customs Enforcement head Ron Vitiello, who worried not about the ethical implications of such a scenario but about the resources needed to carry it out effectively.

The two were ousted from their positions by President Donald Trump weeks later, in part because of their objections to the proposal, reported the Post.

The number of people illegally crossing the southern border has sharply risen in the past few months. U.S. Customs and Border Protection apprehended over 109,000 people at the border in April ― more than double the number of migrants detained during that month last year. A majority of the migrants apprehended were either families traveling together or unaccompanied kids.

The White House’s plan, which is reportedly still under consideration, was to arrest parents and children in 10 U.S. cities with large immigrant communities such as New York City and Los Angeles. The targeted individuals would already be subject to final deportation orders by an immigration judge, the Post and AP reported.

“There was concern that it was being hastily put together, would be ineffective and might actually backfire by misdirecting resources away from critical border emergency response operations,” a DHS official told the Post.

Nielsen and Vitiello also reportedly worried the raids would spark another round of intense public outrage over the Trump administration’s crackdown on undocumented immigrants. Nielsen’s enforcement of the “zero tolerance” policy last summer, which separated children from parents who illegally crossed the border, drew nationwide protest.

Neither the White House nor DHS immediately responded to HuffPost’s requests for comment.