Department of Homeland Security (DHS) Secretary Alejandro MayorkasAlejandro MayorkasNumber of migrant children in US custody passed 15,000: reportSunday shows preview: Biden administration grapples with border surge; US mourns Atlanta shooting victimsMexico launches measures to limit border crossings from GuatemalaMORE on Sunday urged migrants not to travel to the United States, as the Biden administration struggles with a surge of incomers, especially unaccompanied minors, at the southern border.

The message is quite clear, do not come. The border is closed, the border is secure, Mayorkas told host Martha Raddatz on ABCs This Week.

We are encouraging children not to come. Now is not the time to come. Do not come, the journey is dangerous. We are building safe, orderly and humane ways to address the needs of vulnerable children. Do not come, Mayorkas added.

“The message is quite clear: do not come.”

As the border sees a surge in migrants seeking asylum, @MarthaRaddatz presses DHS Sec. Alejandro Mayorkas on the administration’s messaging on immigration. https://t.co/bDt05PIrO4pic.twitter.com/frfqm68FLM

This Week (@ThisWeekABC) March 21, 2021

On Saturday, the U.S. government was housing approximately 15,500 unaccompanied migrant minors, CBS News reported, including 5,000 teenagers and children in Border Patrol facilities not equipped to handle them.

The Border Patrol facilities are also housing migrants for 136 hours on average, which exceeds the 72-hour limit, the network noted.

Mayorkas said on Sunday that the U.S. has seen large numbers of migration in the past, adding that the administration knows how to address the situation.

We know how to address it. We have a plan, we are executing on our plan, and we will succeed. This is what we do, Mayorkas said.

He noted, however, that it takes time, noting that controlling the situation at the border right now is particularly challenging and difficult because the entire system under United States law that has been in place throughout administrations of both parties was dismantled in its entirety by the Trump administration.

So we are rebuilding the system as we address the needs of vulnerable children who arrive at our borders, Mayorkas said.

In an interview broadcast last Tuesday, President BidenJoe BidenBiden hampered by lack of confirmationsLouisiana special election to replace Richmond heads to runoffLarry Summers blasts .9 T stimulus as ‘least responsible’ economic policy in 40 yearsMORE also urged migrants not to make the journey to the U.S.  

“I can say quite clearly don’t come over,” he told ABC News. “Don’t leave your town or city or community.”