'We will not stand for this': Trump fires latest shot in escalating fight over Canada dairy imports

President Donald Trump continued blasting Canada on Tuesday over what he portrayed as price fixing that is unfairly harming US dairy producers.

"Canada has made business for our dairy farmers in Wisconsin and other border states very difficult. We will not stand for this. Watch!" Trump wrote on Twitter.

In the past week, the president has repeatedly criticized Canada over its dairy supply management system, which regulates dairy production and pricing to attempt to prevent surpluses and deficits.

Canada recently lowered the prices for a type of ultra-filtered milk, resulting in a decrease in imports from dairy producers in northern US states like Wisconsin and New York.

"What they've done to our dairy farm workers is a disgrace. It's a disgrace," Trump told reporters in the Oval Office last week.

Some Democrats have publicly supported the president in the dispute, particularly those from states affected by the new pricing policy.

New York Gov. Andrew Cuomo sent a letter to Canadian Prime Minister Justin Trudeau urging the country to come to an agreement with US dairy producers, while New York Sen. Chuck Schumer backed Trump's opposition to the Canadian policy.

For his part, Trudeau has said Trump was misunderstanding the Canadian import market, pointing to US's dairy-trade surplus with Canada.

"The US has a $400 million dairy surplus with Canada, so it's not Canada that's the challenge here," Trudeau said last week in an interview with Bloomberg.

"Let's not pretend we're in a global free market when it comes to agriculture. … We have a supply management system that works very well here in Canada," he said. "The Americans and other countries choose to subsidize to the tune of hundreds of millions, if not billions of dollars, their agricultural industries including their dairy."

The Trump administration has attempted to fulfill the president's campaign promise to take a harder line on US trade policy by increasingly picking fights with Canadian exporters.

On Monday, the administration leveled a new tariff against Canadian softwood lumber importers, accusing the country of unfairly subsidizing softwood sales to the US. The lumber dispute has been a flashpoint of US-Canada trade relations for decades.

Michelle Mark contributed to this report.