Canadian Prime Minister Mark Carney is making his second visit to the White House in five months and is under increasing pressure to address US tariffs on steel, autos, and other goods that are hurting Canada's economy.
"I think they're going to walk away very happy," Trump said, referring to Canada, in Oval Office remarks ahead of a meeting with Carney.
"We're going to treat people fairly. We're going to especially treat Canada fairly."
Trump, complaining that "we're the king of being screwed" by trading partners, said Washington would continue to target some Canadian exports.
Carney initially responded to tariffs by pushing for a separate trade and security deal with the United States, but as talks ran into trouble, he switched his attention to a review of the US-Canada-Mexico free trade deal scheduled for next year.
"We can renegotiate it, and that would be good, or we could just do different deals," said Trump.
"We might make deals that are better for the individual countries."
Asked for his preference, he replied: "I don't care. I want to make whatever the best deal is for this country, and also very much with Canada in mind."
In March, Carney took over as prime minister from Justin Trudeau, who had famously bad relations with Trump.
Carney and Trump have since underlined how well they get on.
"From the beginning, I liked him, and we've had a good relationship," Trump said.
"We have natural conflict. We also have mutual love ... you know we have great love for each other," he added.
In response, Carney called Trump a transformative president.
Trump interrupted Carney as he listed the president's accomplishments to add: "the merger of Canada and the United States," drawing laughter from reporters before adding, "I'm only kidding".
Carney, also laughing, responded: "That wasn't where I was going".
Canada sends 75 per cent of all exports to the United States and is particularly vulnerable to US trade action.
Trump said the two countries have agreed to work together on a missile defence shield dubbed Golden Dome.
"There are areas where we compete, and it's in those areas where we have to come to an agreement that works. But there are more areas where we are stronger together, and that's what we're focused on," said Carney.
A Canadian government official and several analysts played down the chances of an imminent trade deal with Trump and said the fact discussions are continuing should be considered a success for Carney.
The prime minister last visited the Oval Office in May, when he bluntly said Canada would never be for sale in response to Trump's repeated threat to purchase or annex Canada.
Since then, the prime minister has made numerous concessions to Canada's biggest trading partner, including dropping some counter-tariffs and scrapping a digital services tax aimed at US tech companies.
While the majority of Canada's exports are entering the United States tariff-free under the US-Canada-Mexico free trade agreement, tariffs have pummelled Canada's steel, aluminium, and auto sectors and a number of small businesses.
Doug Ford, premier of the Canadian industrial province of Ontario, reiterated calls for Carney to be prepared to be tougher with Trump.
"I'd take a different approach - try to get a deal. If you can't, we got to hit him back hard and never stop hitting him back hard, because we can never take a back seat to anyone, especially President Trump," he told reporters.
The trade war is straining bilateral ties.
Ford in March threatened to cut off electricity exports to New York state and has ordered provincial liquor stores to boycott US alcohol.
Canadians are also shunning travel to the United States.
