Fox News judicial analyst Andrew Napolitano dismissed President Donald Trump‘s threat to permanently shut down the Southern Border as illegal on Fox News Monday.

“Mexico should move the flag waving Migrants, many of whom are stone cold criminals, back to their countries,” Trump tweeted Monday morning. “Do it by plane, do it by bus, do it anyway you want, but they are NOT coming into the U.S.A. We will close the Border permanently if need be. Congress, fund the WALL!”

Mexico should move the flag waving Migrants, many of whom are stone cold criminals, back to their countries. Do it by plane, do it by bus, do it anyway you want, but they are NOT coming into the U.S.A. We will close the Border permanently if need be. Congress, fund the WALL! — Donald J. Trump (@realDonaldTrump) November 26, 2018

“Can he do that?” Fox News anchor Sandra Smith asked.

“He cannot legally do it,” Napolitano said, citing federal statutes.

“Look, he doesn’t have to tolerate lawlessness, and certainly the officials at the border can use reasonable resistance to lawlessness,” Napolitano said. “But the law says if you have a bonafide asylum claim, meaning you’re escaping a government that is pursuing you, or escaping a government that is failing to enforce basic law and order, you can enter the United States.”

“The president doesn’t want to hear this but this is the law,” he said.

Watch above, via Fox News.

Have a tip we should know? [email protected]