WATCH: Reporter challenges Trump on his immigration facts

During President Donald Trump's remarks on a new national emergency at the U.S.-Mexico border, a reporter pushed back against the president's characterization of immigration and crime, asking: "What do you base your facts on?"

The reporter pointed to statistics that show that illegal immigration is down and that drugs come through official ports of entry, not outside them, as Trump often claims.

"I use many stats," Trump said, after telling the reporter to repeatedly sit down.

More fact checks:

• Trump says there's a 'crisis' at the border. Here's what the data says
• How Trump has already changed immigration policy
• Trump says walls work. It's much more complicated
• 4 myths about how immigrants affect the U.S. economy