The president also wrote that Canada must treat US farmers better and Mexico must do more to stop drugs from getting into the United States. "Highly restrictive. Mexico must do much more on stopping drugs from pouring into the U.S". "Millions of people addicted and dying", Trump wrote.
But he added: "If they aren't going to make a fair NAFTA deal, we're just going to leave it this way".
Trump tweeted on Friday that a trade war would be "good, and easy to win".
Trump has been railing about this dynamic for decades, and on Monday he showed no sign of backing down from his hard-line stance.
Trump Blocks Broadcom's Bid for Qualcomm
In an effort to alleviate these concerns, Broadcom has been rushing to redomicile (legally move the company) to the United States. Qualcomm is now involved in intense litigation with Apple around patents and accusations of anti-competitive behaviour.
Serena Williams gears up to launch her own beauty line
Still showing some rust from her long layoff, Serena hit just one ace and made 37 unforced errors to 32 for Bertens. There have been so many days, even still, that I'm like "how am I going to keep going"? "Yeah, I have come so far".
He also cooled down some of the rhetoric coming from Trump about a potential trade war.
"Canada would view any trade restrictions on Canadian steel and aluminum as absolutely unacceptable", the statement read.
If the USA can impose these tariffs on steel and aluminum on the basis of "national security", someone else is sure to try for tariffs on food, or clothing, or various other products on the same basis.
U.S. President Donald Trump and first lady Melania Trump meet with Israel Prime Minister Benjamin Netanyahu and Sara Netanyahu in the Oval Office of the White House March 5, 2018 in Washington, DC. China's National People's Congress spokesperson Zhang Yesui has already threatened to retaliate if the U.S. goes ahead with the proposed steel/aluminium tariffs.
31% of people surveyed by Quinnipiac University said they support the steel and aluminum tariffs.