WASHINGTON — The Trump administration moved Monday to impose a 20 percent tariff on softwood lumber entering the United States from Canada, escalating an intensifying trade dispute between the two countries.

The president announced the decision during a gathering with conservative media outlets at the White House Monday evening.

On Twitter, Breitbart News White House correspondent Charlie Spiering quoted Trump as saying, “We’re going to be putting a 20 percent tax on softwood lumber coming in — tariff on softwood coming into the United States from Canada.”

The Commerce Department later announced it had reached a preliminary determination and would impose countervailing duties ranging from 3 percent to 24 percent on imported softwood lumber, with an average of about 20 percent.

The U.S. and Canada typically enjoy a friendly trading relationship, but things have soured in recent months.

Trump has been railing against Canada’s decision to change its policy on pricing domestic milk to cover more dairy ingredients, leading to lower prices for products, including ultra-filtered milk. Trump has called the move “a disgrace” that’s hurting U.S. producers in dairy states like Wisconsin.