The only way to alleviate the influx of children from Central America now at the southwest border is to ship them back to their home nations, Sen. John McCainJohn Sidney McCainOvernight Defense: Pompeo lays out new Iran terms | Pentagon hints at more aggressive posture against Iran | House, Senate move on defense bill Senate GOP urges Trump administration to work closely with Congress on NAFTA Sarah Sanders: ‘Democrats are losing their war against women in the Trump administration’ MORE (R-Ariz.) said on Sunday.

“There has to be a halt to this,” McCain said on CNN’s State of the Union. “The best way to do that is to send plane loads of people … to their country of origin.”

While the situation along the border is “tragic and terrible … we cannot have an unending flow of children from all over the world” come to America, he said.

McCain derided President Obama's $3.7 billion request to deal with the ongoing crisis as not enough, saying at least $6 billion would be need. However, some House Republicans have said the administration’s request is already too much.

McCain called on the administration to address the “root causes” of the crisis, namely the living conditions in the countries where the children come from.

He said the U.S. should beef up its presence at embassies and consulates in Central America and change trafficking laws to show “that if you come to this country illegally, you will be sent back.”

Unless the White House does that, parents will continue spending money to send their children to the border, according to McCain.

“It won’t matter how much money we spend, if they believe they can come here and stay,” he said.