US president Donald Trump's continuing reliance on tariffs could significantly reduce the likelihood of the new USMCA trade agreement coming to fruition, it has been argued.

Senior fellow at the Competitive Enterprise Institute and trade policy expert Ryan Young said that while the new NAFTA/USMCA is supposed to be Mr Trump's top domestic priority, his tariff-heavy bargaining strategy means steel and aluminium continue to be a major sticking point.

He pointed out that tariffs on the metals are meant, in part, to be a way of encouraging Mexico and Canada to acquiesce to the US's demands, but they are in fact leading to resentment and delays.

"Mexico and Canada are both offended that a close ally is publicly calling them national security threats. They are withholding cooperation," Mr Young commented.

Indeed, many democrats in Congress and even some republicans want the tariffs on steel and aluminium to be repealed if it would mean the USMCA being pushed forward, but Mr Trump has so far been unwilling to do this.

"Unfortunately, the president is committed to his tariff strategy and likely will continue to double down on failure. Tariffs are even more harmful to the US economy than they are to US foreign policy interests," Mr Young concluded.

Last month, there had been hopes the USMCA would be ratified by all three countries' governments before the Mexican legislative session ended on April 30th 2019, but this did not prove to be the case.

The US Congress has also not officially taken up the USMCA yet, despite Mr Trump urging it to do so during his 2019 State of the Union address in a bid to "deliver for American workers like they have not [been] delivered to for a long time".

If Congress does not ultimately ratify it, the US may potentially withdraw from NAFTA.