Trump said the climbers invited to participate were "very good" – "some of them were champions" – and the bollard style barrier "can't be climbed."

"This is very, very hard," the president said.

Lucy Hancock, an 8-year-old from Kentucky, is proving otherwise.

The girl's mother posted a video to Facebook this week of the third-grader scaling an exact replica of the 18-foot wall going up along miles of the southern border, and it took just over a minute for the youngster to crest the structure.

"Remember that border wall replica build by Rick Weber for a competition next weekend in the Red River Gorge?" Karla Hancock posted. "We were able to help perform preliminary testing of the belay system this weekend. Lucy declared it an easy 5.7 with a tough dyno finish."

The "belay system" Hancock referenced is a safety device climbers use to prevent a fall.

Weber, co-founder of the local Muir Valley rock climbing park, told Time he decided to construct the wall replica after watching the president boast about the "virtually impenetrable" border wall in San Diego.