The clip he tweeted is from September 2018, and it shows construction work on a barrier that already existed.
— Donald J. Trump (@realDonaldTrump) February 20, 2019
THE WALL IS UNDER CONSTRUCTION RIGHT NOW! https://t.co/exUJCiITsz
— Donald J. Trump (@realDonaldTrump) February 21, 2019
President Trump tweeted a time-lapse video of work along the border wall in New Mexico: "Many miles more now under construction."
— MSNBC (@MSNBC) February 21, 2019