The Biden administration is working to find more room for the increasing number of unaccompanied migrant children crossing the U.S.-Mexico border, White House Press Secretary Jen Psaki said Tuesday.

As of this week, there are more than 3,200 kids in Customs and Border Protection care, according to new data obtained by The New York Times, a threefold increase in the last two weeks.

Under the law, migrant children must be transferred out of those border facilities within 72 hours, since they aren’t designed for long term use or for kids. But a lack of capacity in separate shelters – which are meant to house minors and offer things like medical services and education – is creating a backlog.

On Tuesday, the press secretary said a “humane approach” to minors crossing the border is one of President Biden's top priorities, and she said policy teams were working to get them transferred to shelters “as quickly as possible.”

“That includes looking at additional facilities,” Psaki said in a White House briefing Tuesday. “We're also looking for ways that we can expedite the way that we vet and process families and sponsor host families where these kids can go.”

Psaki said the administration aims to create “an effective, moral, humane system” for border migration, but she did not detail how their strategy would differ from previous presidencies, which also used shelters to detain migrant children. 

Last week, a group of senior administration officials traveled to the border to visit a CBP facility and one of the shelters housing kids, which are overseen by the Department of Health and Human Services.

The White House published a short summary of the visit, but the press secretary said they are waiting to brief the president on the trip before providing more details to the public.

At the border, officials are still turning away the vast majority of immigrants who cross under a public health order that remains in place from President Trump’s term. However, officials are now taking in unaccompanied children as a change in policy, a potential reason for the surge in recent weeks.

While border crossings have been steadily increasing since April 2020, the number of unaccompanied minors topped 5,800 last month, slightly higher than the number in January 2019, the year that border crossings reached a recent peak.

On Tuesday, Press Secretary Psaki noted some reasons for the increase in migration, including the pandemic, the hurricanes that hit Central America last year, violence and economic hardship.

Still, officials have reiterated that now is “not the time to come” to the border, especially as the administration seeks to develop a response.

“They need to wait,” Homeland Security Secretary Alejando Mayorkas said in the briefing room last week. “It takes time to rebuild the system from scratch.”

Psaki did not confirm where additional shelters for migrant children might be housed, but Pentagon spokesperson John Kirby said last week that HHS officials have surveyed an army base in Virginia as a potential option.

The White House has also not confirmed the number of children currently in CBP custody or the number of shelter beds needed, but she did promise reporter access to the shelters soon. Video showing kids held within metal fencing at border facilities demonstrated the reality of family separations at the time.

“We're committed to doing that. I don't have a timeline for you at this point in time,” Psaki said Tuesday. “We want to do it with respect for the privacy of the people staying there ... but also abiding by COVID protocols.”

In one effort to open more space to unaccompanied minors, the CDC put out new guidance for HHS shelters last week, allowing them to operate at 100 percent capacity while still using strict COVID-19 mitigation measures, CNN first reported.