(CNN)The number of unaccompanied migrant children in US Border Patrol facilities, which are akin to jail cells and not intended for kids, has reached dramatic highs, according to internal agency documents reviewed by CNN, underscoring the urgent challenge facing the Biden administration.

This February was the coldest in more than 30 yearsMore than 3,200 unaccompanied migrant children were in Customs and Border Protection custody, according to the documents dated Monday. Of those, around 2,600 were awaiting placement in shelters suitable for minors, but there were just over 500 beds available to accommodate them.The latest data comes on the heels of a trip to the US-Mexico border by senior administration officials to assess the situation on the ground amid an increasing number of arrests and indicates a rapidly increasing trend of unaccompanied children coming into the US. Less than a week ago, there were around 1,700 children in Border Patrol custody.

As of Monday afternoon, President Joe Biden had not yet been briefed by his top aides on the weekend trip, which included a visit to a facility for unaccompanied migrant children in Carrizo Springs, Texas — the first facility for migrant children to open since Biden took office.The officials were in fact-finding mode, a person familiar said, and many were taking notes during their conversations. Biden is expected to be briefed in the coming days as aides spent some of the trip comparing notes and planning how to present the information to the President.Among those who went was Susan Rice, former President Barack Obama’s national security adviser who now heads Biden’s Domestic Policy Council. A source familiar with the visit told CNN that Rice was engaged during the visit and, at times, pressed Department of Health and Human Services officials, who run the shelters for unaccompanied migrants, on how they were preparing to respond to the surge and process migrant children more efficiently.“The number of unaccompanied children (UC) in our care is constantly changing,” the department said.

Source: Record number of kids are in Border Patrol custody and shelter beds are scarce, documents show