She also told the border agency, which was overseen by DHS, to look at adding more than 2,000 officers to border areas.
Last week, CBP commissioner Kevin McAleenan said that he moved 750 officers from "key roles" into entry ports to help border patrols provide for immigrants, including helping with processing and transportation, adding that the shift will bring about a slowdown in trade and an increased waiting time for cars and pedestrians who cross legally.
The administration has not provided further details on where the staff would be moved or where they would be deployed.
CBP expected March to be the highest month for southern border meetings in a decade, according to McAleenan. The final monthly numbers have not yet been released.
Nielsen also addressed the immediate expansion of the administration's policy of turning asylum seekers to Mexico during their immigration procedure and calling for "hundreds of additional migrants" to be returned to Mexico every day.
So far, this policy has been in California and parts of Texas, but Nielsen said her department would appear to expand the returns for returns as well.
"The crisis at our border worsens and DHS will do everything to end it," Nielsen said in a statement.
The return policy, known as the Migration Protection Protocol, is being challenged by a group of immigrants who were sent back to Mexico to await their legal dates.
Last month, lawyers seeking to block politics claimed that the relatively new policy was dangerous, illegal and "injured."
However, the administration has argued that "the executive department has wide discretion" over whether deportation procedures against human beings must be illegally introduced in the United States and adopted this policy to "fight the serious problems at the southern border."
Nielsens The announcement comes a few days after President Donald Trump threatened to close the US-Mexico border.
This weekend, the administration said it was cutting off aid to the Central American countries of El Salvador, Guatemala and Honduras, otherwise known as the Northern Triangle, one day after Trump said they had "set up" migrating caravans for entry in the United States. "
" We paid them huge amounts of money and we no longer pay them. Because they haven't done anything for us. They created these caravans, "said Trump Friday.
The majority of immigrants arriving at the southern border are families and unaccompanied children from these Central American countries.
Less than a week before the administration said it would help to the northern triangle countries, Nielsen in Honduras was to sign one what she called a regionally compact agreement with Guatemala, Honduras and El Salvador.
The agreement was aimed at preventing irregular migration, combating criminal organizations and ultimately Helping with US Border Security
"We are united, we are committed, we work together," she said at the signing, but added that "more needs to be done and the United States must see measurable improvements on the map term. "
Meanwhile, Nielsen travels in Europe this week to meet with the UK and Swedish officials before joining the G7 ministerial meeting in Paris, France later this week.