Homeland Security chief urges patience with "stressful challenge" along U.S.-Mexico border

The surging number of unaccompanied minors crossing the U.S.-Mexico border has posed a "stressful challenge" for the Biden administration, Homeland Security Secretary Alejandro Mayorkas acknowledged Monday, while insisting that the influx of undocumented children has not reached a "crisis" level.

"Quite frankly, we are working as hard as we are, not only in addressing the urgency of the challenge, but also in building the capacity to manage it," the newly confirmed secretary said in his debut appearance at the White House press briefing.

U.S. officials along the southern border took roughly 2,000 migrant children into custody last week, according to government data reviewed by CBS News. Nearly 400 children were taken into custody on Friday alone. In January, the last month for which statistics are available, the Office of Refugee Resettlement received more than 4,000 unaccompanied children from immigration officials, a 19% increase from December.