President Trump on Tuesday used Twitter to lay out his case for a wall on the southern U.S. border, just hours before he was set to negotiate the issue with top Democrats.

Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi are standing in his way of the $5 billion he wants for more fencing and concrete wall at the border. But in a series of tweets, Trump warned the two Democratic leaders that he would ultimately get what he wants.