President Donald Trump was mocked over Twitter after announcing Colorado border wall construction plans.

On Wednesday, the president claimed he is going to construct a wall in Colorado. “We’re building a wall in Colorado, we’re building a beautiful wall, a big one that really works, that you can’t get over, you can’t get under,” Trump said.

Colorado does not share a border with Mexico. Gov. Jared Polis (D-Colorado) mocked him for not understanding basic geography.

Rep. Diana DeGette (D-Colorado) also joined in on the social media criticism.

The president defended himself early Thursday morning.