In a heated Twitter rant on Sunday, the US president lashed out at the Mexican authorities, who in his words do nothing to prevent illegal migrants from infiltrating the US’ southern border, allowing large inflows of illegal migrants and drugs to pour into the country. He also threatened to drain the "cash flow" into Mexico by breaking the existing free trade deal and once again reiterated that the United States needs a wall on the border with its southern neighbor.
The United States, Canada and Mexico have been negotiating an update of NAFTA since 2017. Trump considers NAFTA unprofitable for the US, repeatedly threatening to withdraw from the deal.
The NAFTA agreement has been in force since 1994. Its participants, the United States, Canada, and Mexico, have a population of just under 500 million and a GDP of about $21 trillion.