The US is thinking about separating children from their parents if caught illegally crossing the Mexico border.
Homeland Security Secretary John Kelly told CNN the move would be an attempt at stopping families from making the perilous journey from Central America.
Tens of thousands of parents and children, many who are fleeing violence in Honduras and El Salvador, have been detained coming across the border.
President Donald Trump made border security a key campaign pledge.
His vow to build a wall on the Mexican border was very popular among his supporters.
Media reports on Friday suggested the new policy would mean parents being kept in custody while they go through the legal or deportation process.
But their children would be looked after by the Department of Health and Human Services (HHS) until they can be taken into the care of an American relative or a state-vetted guardian.
When asked about these media reports on Monday, Mr Kelly said: “Yes, I am considering – in order to deter more movement along this terribly dangerous network – I am considering exactly that.
“They will be well cared for as we deal with their parents.”
He would do “almost anything” to deter people from Central America getting on this “very, very dangerous network” and going through Mexico, he said.
Democratic Congressman Henry Cuellar, a Texas Democrat who has a district about 200 miles (320 km) from the border, has criticised the proposal to separate families.
He said: “Bottom line: separating mothers and children is wrong. That type of thing is where we depart from border security and get into violating human rights.”
In 2014, when President Barack Obama was in the White House, the number of unaccompanied children detained at the border reached crisis levels, with more than 50,000 caught that year.
Others travelled with parents and detention centres were set up to house families while their cases were being heard.
But a federal judge in California ruled that keeping children in these centres was unlawful, even with their parents, so the families were released into the US.
One former Department of Justice official, Leon Fresco, said separating children from parents was under consideration in the Obama administration, ever since that court decision.
Hours before Mr Kelly’s comments, President Trump signed an executive order temporarily banning all refugees and all visitors from six mainly Muslim countries, due to terror fears.
Stories from the US-Mexico border
US ‘may split families that cross border’