When the new Canadian prime minister arrived at the Oval Office on Tuesday morning to meet with the American president, he appeared to be walking into a lion’s den. But it turned out to be a house cat he found there.

“Canada is a very special place to me,” President Trump purred at the top of the meeting. “I know so many people that live in Canada. My parents had relatives that lived in Canada, my mother in particular.”

This was somewhat surprising, since he had just spent months growling about how he would like to gobble up Canada and turn it into the 51st state.

“I love Canada,” Mr. Trump added.

It was a decidedly different tone from the one he had used just moments earlier in a post on Truth Social, when he blasted Canadians as a bunch of freeloaders who couldn’t survive without the United States. He posted this just as the new Canadian prime minister, Mark Carney, was arriving at the White House.

But now the man leading the nation that Mr. Trump had been picking on was sitting right beside him — inches away!

“Canada loves us and we love Canada,” Mr. Trump said now.

A reporter asked him what was the top “concession” he hoped to extract from his neighbors to the north.

“Concession?” said Mr. Trump. “Uh, friendship.”

As the meeting banged along, Mr. Carney kept an uneasy grin pasted on his face and fidgeted with his hands. He never quite dropped his guard. Mr. Trump, on the other hand, had the look of a man coming face to face with the consequences of his own actions and not quite wanting to deal with them.

He and the people who work for him in the White House got great amusement these last few months from referring to Canada as a “state” and addressing Mr. Carney’s predecessor, Justin Trudeau, as a “governor.” Mr. Trump posted maps and memes of the two countries with the border between them erased, even as he insisted to Time magazine last month, “I’m really not trolling.”

It all resulted in this meeting with his Canadian counterpart that should have been fairly anodyne, as it would have been under any other administration, but which was now freighted with anger, awkwardness and a thin scrim of recrimination. Mr. Trump did not appear to be in the mood to deal with any of the complications that his “not trolling” had created.

Mostly he mostly tried to skate around them, tossing out a ton of other topics that were not even tangentially connected to his tête-à-tête with the Canadians. Topics such as the construction schedule of Barack Obama’s presidential library in Chicago; Gov. Gavin Newsom of California; a high-speed rail line in California; weapons left behind in Afghanistan; “a very, very big announcement” Mr. Trump claimed he would soon be making but which was for now to remain a secret, so he couldn’t really say what it was yet, only that it was going to be “like, as big as it gets”; diplomacy with the Houthis in Yemen; and, as always, former President Joseph R. Biden Jr.

Mr. Carney made clear he was not there to countenance any more nonsense about a 51st state. “There are some places that are never for sale,” he said, firmly. Mr. Trump would occasionally try to get in a last word (“never say never!”) but his heart did not seem to be in it. “Well, I still believe that,” he said of this idea of his that had caused so much trouble. “But, you know,” he continued, placidly, “it takes two to tango, right?”

Some of the usual characters who play minor roles in these Oval Office dramalogues sat on the couch to Mr. Trump’s left. There was Vice President JD Vance, Secretary of State Marco Rubio, and the commerce secretary, Howard Lutnick, ready to jump in if needed.

But they never did.

The unspoken directive from the president seemed clear: Everybody be cool.

“This is very friendly,” Mr. Trump said to the room. “This is not going to be like — we had another little blowup with somebody else, that was much different. This is a very friendly conversation.” The couch chuckled, relieved.

“Regardless of anything,” Mr. Trump declared at one point, “we’re going to be friends with Canada.”