President Donald Trump thanked CNN reporter Jim Acosta on Friday for filming a video on the Southern border with a steel barrier on it.

“Good job yesterday,” Trump said to Acosta after spotting him at the White House. “I appreciate your sales pitch.”

Acosta filmed a video of a “steel slat” barrier on the Southern border, noting that there was no crisis there, which prompted wide-spread mockery on Twitter from Trump supporters.

“I didn’t see any danger on the border Mr. President,” Acosta replied.

“That’s because we had a wall,” Trump replied.

“There were portions that didn’t have a wall,” Acosta replied, as reporters left the room.

Trump ignored Acosta’s response and continued, “Some people are dumb. Great promotion for us.”

Trump and Acosta exchanged words after the president hosted a law enforcement roundtable at the White House on the importance of building a wall.