President Donald Trump on Saturday issued a new threat to terminate the North American Free Trade Agreement altogether, warning Congress not to intervene in tough negotiations that may or may not include Canada in a new accord.

Trade talks between the United States and its 2nd largest bilateral trading partner will kick off again Wednesday, after the two sides ended Friday's tense negotiations without a deal. The talks were thrown into doubt after the president reportedly made an off-the-record comment that was published, suggesting he wouldn't give Canada any leeway.

In a series of posts on Twitter, Trump took an uncompromising stance with the U.S.'s neighbor to the north. He said there was "no political necessity" to keep Canada in a new deal that Mexico appears to have agreed with in principle.

Both Democrats and Republicans have voiced skepticism about Trump's negotiating stance, and whether it was viable in the context of keeping Canada in a new accord.

"If we don't make a fair deal for the U.S. after decades of abuse, Canada will be out. Congress should not interfere with these negotiations or I will simply terminate NAFTA entirely & we will be far better off," the president added, blasting the trade pact as one of "the worst deals ever made."

Trump

Still, the United States enjoys a goods and services surplus with Canada, which data from the U.S. Trade Representative showed totaled over $8 billion last year. That figure comes with a caveat, according to the USTR.

"However, the international shipment of non-U.S. goods through the United States can make standard measures of bilateral trade balances potentially misleading," a USTR fact sheet said.

"For example, it is common for goods to be shipped through regional trade hubs without further processing before final shipment to their ultimate destination. This can be seen in data reported by the United States' two largest trading partners, Canada and Mexico," it added.

On Friday, Trump notified Congress that he wants to sign a trade agreement with Mexico, and potentially Canada in 90 days, the period legally required to review a deal, U.S. Trade Representative Robert Lighthizer said in a statement. The neighbors emerged from talks Friday, the White House's deadline for Canada to join in on a deal the U.S. struck with Mexico earlier in the week, without resolving sticking points.

Trump has sought to revise the three-nation trade agreement, which he says has punished American workers since it went into effect more than 20 years ago. The president has used tariffs on Canadian and Mexican goods to bring the countries to the negotiating table and wants them to drop their own barriers on certain products.

The White House is on track to provide text of a deal to revise NAFTA to Congress within 30 days, and Trump would aim to sign it 60 days after that, senior administration officials said Friday. They believe the administration would comply with the conditions for so-called fast-track trade authority, which would allow a deal to get through Congress more easily, even if Canada does not join in the deal.

However, some lawmakers are worried that a bilateral deal would not pass legal muster, according to Reuters.

The U.S. has focused in particular on Canada's agricultural policy, which Trump contends has unfairly curbed sales of U.S. dairy products there. He also aims to boost American farmers in Midwestern states who helped to propel him to the White House. Many of those farmers have taken a hit from the effects of the White House's mounting trade conflicts with China, Canada, Mexico and the European Union.