Washington DC - President Donald Trump threatened to impose new and "severe" tariffs on Canadian fertilizer exports in a desperate bid to help US farmers who have struggled throughout his global trade war.

Trump's comments came while fielding questions from reporters during a roundtable at the White House on Monday that featured Agriculture Secretary Brooke Rollins, Treasury Secretary Scott Bessent, and other high-ranking figures.

During the event, Trump announced a $12 billion tariff relief fund for US farmers, who are facing steeply increasing prices for imported agricultural necessities like seed and fertilizer.

When asked about how he plans to help US fertilizer production, Trump said that he'll impose "severe tariffs" in an attempt to reduce domestic costs.

"A lot [of fertilizer] does come in from Canada, and so we'll end up putting very severe tariffs on that, if we have to, because that's the way you want to bolster it here, and we can do it here," Trump said.

Rollins also emphasized the importance of re-shoring fertilizer production into the US to help provide local farmers with a cheaper domestic supply.

"The president has been very unequivocal in saying we have to figure out why all these input costs are skyrocketing," she said.

Canada is the world's largest producer of potash, a key ingredient in commercial fertilizers, and exports more than 95% of their supply. Other than that, potash is only really exported from Russia, Belarus, and China.

Amid backlash for sending the cost of fertilizer through the roof earlier this year, Trump had already been forced to backtrack on his 25% blanket tariff regime and introduce an exemption that set levies at 10% for Canadian fertilizers.

Trump's suggestion that he might once again raise tariffs on fertilizers has prompted an immediate backlash, with experts warning that it'll once again send prices skyrocketing – not falling.

Veronica Nigh, a senior economist at the Fertilizer Institute, which is based in the US, told CTV News that Trump's threats feel "a bit like déjà vu."

"It feels like we had to explain to the world how important Canadian reserves and exports of potash globally, and specifically to the US, were earlier this year when we were talking tariffs, and so of course this is not a welcome comment from the president," Nigh explained.

"As all Canadians know, and most Americans, I think, at this point, the US is incredibly reliant on Canada for our potash needs," she said.

"There's a lot of cross-border trade that occurs in many other fertilizers that are really beneficial."

"There are only three major exporters in the world – Russia and Belarus are the other two sources of major potash reserves," Nigh warned. "I think most Americans would agree that we’d much rather get our potash from our friends."