Mexico isn't going to write a check to the U.S. to pay for Donald Trump's proposed border wall, according to Real Money contributor Steve Blitz. But Trump may try to renegotiate the trade deals between the two countries. As of 2015, the U.S-Mexico trade deficit stood at roughly $49 billion. President Trump may try to narrow that gap, which would also boost gross domestic product, according to Blitz. In an interview with ABC News, Trump said construction on the wall could begin in "months."