Acting White House Chief of Staff Mick Mulvaney defended the Trump administration’s plan to cut off aid to three Central American countries, saying El Salvador, Guatemala and Honduras could do more to curb the flow of illegal immigrants into the United States.

The State Department said in a statement on Saturday that it would end millions of dollars in funding to the three countries that make up the Northern Triangle as the flow of immigrants crossing Mexico into the US has increased.

Mulvaney, who also serves as the White House budget director, said Congress could step in to help solve immigration problems at the border, “but they’re not going to.”

“Mexico could help us do it, they need to do a little bit more. Honduras could more more. Nicaragua could do more. El Salvador could do more,” he said on CNN’s “State of the Union.” “And if we’re going to give these countries hundreds of millions of dollars, we would like them to do more. That’s not an unreasonable position.”

The action came after President Trump on Friday threatened to shut down the US-Mexican border after Customs and Border Protection Commissioner Kevin McAleenan said the border has reached a “breaking point” and predicted that more than 100,000 illegal immigrants will cross into the US this month.

CNN host Jake Tapper questioned whether withholding that money will cause the problems of crime and economic uncertainty in those countries to become worse and exacerbate the immigration problem.

“If it’s working so well, why are the people still coming? Why are these historic numbers? Again,100,000 people will cross the border this month alone,” Mulvaney said. “That is a crisis, it’s a humanitarian crisis, it’s a security crisis. … The proof is in the numbers, it’s not working well enough to help solve our border problem and that’s what the president’s focused on.”