President Donald Trump late Tuesday slammed the brakes on a wave of tariffs that were set to hit Canada at midnight.

On social media, Trump wrote: "I have paused the 50% Tariffs against Canada, that were scheduled to kick in tomorrow morning for a three day period, based on the fact that Canada and the U.S.A., subject to the finalization of documents, have a DEAL!"

Trump did not provide further details, except to refer to the Keystone XL pipeline, which he said "may be awoken from the grave!"

"The deal will include comprehensive market access for all American goods, economic security commitments, digital trade alignment, and many important provisions that will continue to protect our market and American workers, along with our Canadian partners," the Office of the U.S. Trade Representative said in a separate social media post.

In a statement, Canadian Prime Minister Mark Carney said the postponement of tariffs would last until the end of the day Friday.

"Substantial progress has been made, although there is important work still to be done," he said.

The 50% duties would have affected about $20 billion worth of U.S. imports from Canada, according to the trade representative's office. The import taxes would have hit products ranging from hockey sticks to some building materials, liquors and certain kinds of clothing.

The last-minute deal came after more than a week of furious meetings and technical talks.

On Monday afternoon, Carney described the talks with the Trump administration as "very delicate and intense" but did not provide any further details. Carney and Trump spoke later that afternoon and again late Tuesday, Carney's office told NBC News.

In his statement late Tuesday, Carney acknowledged the "intensive discussions." He added that his government was aiming to "deliver greater certainty and real benefits for Canadian businesses, workers, farmers and families."

"While we continue this work, Canada remains focused on building a stronger, more independent, and more competitive economy at home," he said.

Carney has previously said the threatened duties were a "direct violation" of the U.S.-Canada-Mexico Agreement, which Trump pursued and signed in his first term.

The U.S. Chamber of Commerce warned in a statement Tuesday that in the event of no deal, "the introduction of higher tariffs would damage both economies, drive up costs for U.S. families, further disrupt critical supply chains, and risk the 13 million American jobs that depend on" the North American trade pact.

The tariffs that were set to be imposed would have been the first use of Section 338 of the Tariff Act of 1930. The law allows the White House to implement duties of up to 50% on any foreign trading partner that "discriminates" against U.S. commerce.

In talks with their counterparts, Canadian officials were seeking not only to have the Section 338 tariffs scrapped entirely, but also to lower Section 232 tariffs on industrial products such as steel and aluminum, CBC News and Bloomberg have reported.

The Chamber of Commerce said Tuesday that lower duties on Canada would be "a boon to U.S. consumers, producers, farmers and manufacturers."

A sticking point Monday and Tuesday appeared to be a request for lower automobile duties, according to Bloomberg and Reuters, which also reported that U.S. officials did not want to cut current 25% tariffs on that sector to anything lower than 15%.

Trump did not say in his brief social media post whether the duties would be lowered.

U.S. Trade Representative Jamieson Greer said earlier that the reasoning behind the threatened 50% duties was effectively payback for Canada's retaliation against previous tranches of Trump's tariffs.

"The policy basis for [Wednesday's] duties are related to measures that Canada took against the United States," Greer said last week. "I've got two countries in the world that have retaliated against the United States for trade measures: the People's Republic of China and Canada. That's not the kind of company you really want to be running in."

Last year, Trump briefly responded to China's retaliation by raising tariffs into the triple digits. Talks between Treasury Secretary Scott Bessent and China's vice premier over months eventually defused that tension, and tariffs were lowered.

Trump has also aimed his anger at Canada repeatedly. At one point, he became enraged by the province of Ontario, which ran a TV ad during 2025 World Series telecasts. The video used edited clips of Republican former President Ronald Reagan to criticize Trump's trade policy.

Trump halted trade talks with Canada and later accused the Canadian government, which did not sponsor the ad, of interfering with the Supreme Court's deliberations over his tariffs; the court later ruled that he overstepped his legal authority.

Trump threatened 10% extra tariffs on Canada after the ad but never followed through. Ontario later pulled the ad from the airwaves.

This article was originally published on NBCNews.com