The Trump administration could be holding 30,000 illegal immigrant children by the end of August as a result of its push to enforce federal immigration laws, which has led to the separation of children from their parents and guardians as those adults are prosecuted.

A senior administration official who asked not to be identified said the Department of Health and Human Services has been taking in about 250 children per day in recent weeks. HHS is the agency that is taking in children when they are separated from their families.

An HHS official added that the agency expects to be taking about 250 kids each day at least for the next two months. If that estimate holds, HHS could be caring for 18,500 more children by the end of August.

The HHS official said as of Friday, HHS was already holding 11,500 children, which means the total could hit 30,000 by August.

The practice of separating children from illegal immigrant adults has become highly controversial in the last few weeks, and is something Democrats have highlighted as a practice that needs to stop.

[Related: GOP looks to end family separation at the border in immigration bill]

The Trump administration has defended the policy by saying illegal immigrants need to know that if they try entering the U.S., they will be prosecuted, which could lead to separation from their children. Officials have said U.S. citizens face the same risk when they commit crimes.

[Also read: Ted Cruz defends Trump’s policy of separating families of illegal immigrants]

But administration officials have also said they support a change to the federal law that requires prosecution and family separation, and have blamed Democrats for current law.

Illegal immigration along the southwestern U.S. border has spiked in the last few months, even though administration officials have said they expect Trump’s zero-tolerance policy to eventually dissuade more from coming. A Justice Department spokesman told the Washington Examiner last week the zero-tolerance policy is not expected to lead to a decline in the number of illegal immigrants attempting to make the trek to the U.S. from primarily Central American countries until early fall.

Under current practice, HHS takes care of unaccompanied illegal immigrant children as well as now those under the age of 18 who must be cared for while the adults they were apprehended with are prosecuted for illegal entry. This spring, Sessions directed federal prosecutors stationed at the border to bring charges against all migrants that U.S. Customs and Border Protection officers took into custody.

However, family units that arrive at ports of entry and request asylum will not be prosecuted because they have not attempted to enter the country illegally, several DHS officials confirmed to the Washington Examiner. They will also be kept together as they go through the asylum process. These groups are detained in DHS facilities while minors are directed to HHS.

In an attempt to secure housing for the coming flood of children, HHS selected the Tornillo Land Port of Entry near El Paso, Texas, last week as the first back-up site to temporarily house around 360 minors.

The Trump administration is also advancing a plan to tentatively house unaccompanied minors in tent cities located on three Texas military bases due to increasing border apprehensions and a shortage of beds for the underage immigrants.

“[Health and Human Services] is running out of space because of the implications of the zero tolerance policy, but also because we continue to see this uptick in numbers,” an official confirmed to the Washington Examiner last week.

HHS officials are looking at Fort Bliss near El Paso, Dyess Air Force Base in Abilene, and Goodfellow Air Force Base in San Angelo, the official confirmed.