WASHINGTON - US President Donald Trump said on Saturday that there is "no political necessity" to keep Canada in the new North American Free Trade Agreement (NAFTA) deal.

"If we don't make a fair deal for the US after decades of abuse, Canada will be out," Trump said via Twitter, threatening to terminate the 24-year-old trilateral trade deal.

"We were far better off before NAFTA - should never have been signed. we make new deal or go back to pre-NAFTA!", he wrote.

Trump's comments came after the United States and Canada failed to meet a Friday deadline imposed by the Trump administration to revamp the NAFTA trade agreement as major differences remain in bilateral talks.

"Our officials are continuing to work toward agreement," US Trade Representative (USTR) Robert Lighthizer said Friday in a statement, adding the USTR team will resume trade talks with its Canadian counterparts next Wednesday.

The White House has pressured Canada to accept the preliminary agreement it struck with Mexico on Monday to update the trilateral trade deal. But Canada insisted that it would only sign a new agreement that is good for the country.

It is still unclear whether the United States and Canada will work out their differences in the next few weeks.

Trump has threatened to slap additional tariffs on imported autos from Canada if the two sides are unable to reach a new trade deal.

While US officials have indicated that they are prepared to go ahead and sign a NAFTA deal only with Mexico, the US business community and many lawmakers have insisted that the NAFTA deal should remain a trilateral pact.

"Anything other than a trilateral agreement won't win congressional approval and would lose business support," President and CEO of the US Chamber of Commerce, Thomas Donohue, said Friday in a statement.

Talks on renegotiating the NAFTA began in August 2017 as Trump threatened to withdraw from the trilateral trade deal, which he claimed harmed US industries and jobs.