MILWAUKEE -- As Donald Trump prepared to speak at the Republican National Convention, Canada's ambassador to the United States was urging Canadians to talk to Americans about the countries' important relationship.

"If you are at the lake this summer with some American neighbours, just take a moment to remind yourselves and themselves how lucky we are to have each other as neighbours," said Kirsten Hillman, who is attending the convention in Milwaukee.

"And how much prosperity and security we get out of it."

Trump, who is poised to formally accept the Republican presidential nomination, was expected to speak publicly Thursday evening for the first time since an assassination attempt last weekend.

He attended each night of the convention, his right ear covered in a white bandage after being pierced by a bullet when a gunman fired from a rooftop near a Saturday rally in Pennsylvania.

Republican Ed Schlesser said he feels like Trump has shown a new, more resilient and tempered side to his leadership since the shooting.

"He really wants to do it for the whole United States and the world," Schlesser, wearing a red Trump shirt, said near the convention. "You can tell ... he's just feeling it."

The four-day event seemed to invigorated the Republican base behind Trump, with supporters saying the former president will unify the party and the country. Its final day -- with the theme "Make America Great Once Again" -- was expected to lay out Trump's vision for the country.

"Trump will usher in a new golden age for America. At home and abroad, America's standing will be restored," a description of the theme said.

Matthew Lebo, a specialist in U.S. politics at Western University in London, Ont., said any talk of unity across party lines quickly disappeared from convention speakers' talking points throughout the week as their rhetoric became increasingly adversarial.

Lebo said he suspected Trump's speech would be more of the same.

"I didn't buy that that was going to last more than a few hours," he said of the conciliatory tone.

"That's not Donald Trump. That's not the party platform. That's not the party right now."

Some global leaders were reacting to the looming possibility Trump will return to the White House, as President Joe Biden stepped back from campaigning after testing positive for COVID-19 this week at a critical time for the Democrats.

Speculation about Biden's future and mental acuity have been swirling after a disastrous debate performance against Trump last month and multiple missteps at the NATO leaders' summit in Washington last week.

Lebo said Trump can be erratic, and global leaders are worried they can't rely on stability from the U.S.

Concerns over America's role in the world were heightened further after Trump chose Ohio Sen. JD Vance as his running mate.

Vance will just "toot Trump's horn," Lebo said.

The vice-presidential nominee has been a vocal opponent of U.S. military aid to Ukraine as it fends off Russia's invasion. In addition, Trump has repeatedly said he would not defend NATO members that don't meet defence spending targets.

Prime Minister Justin Trudeau has promised to meet NATO's target, the equivalent of two per cent of gross domestic product, by 2032. But he has been criticized for the lengthy timeline and the lack of detail on how Ottawa will make it happen.

Several premiers have urged Canada to meet the NATO spending target, stressing a need to preserve bilateral relations.

"For Canada and its relationship with the United States -- we are significant trading partners -- we want them to respect us fully, in all aspects, including our ability to honour obligations," said Nova Scotia Premier Tim Houston at the Council of the Federation meeting this week in Halifax.

Trump has also mused about higher duties on foreign goods, suggesting a blanket 10 per cent tariff on nearly all imports.

In an interview, Hillman said the United States is a "noisy ecosystem," and it takes a lot of work to ensure information about the Canadian relationship gets through. But, she said, it's extremely important to ensure Americans understand that Canada's success is their success.

Hillman said she has met with senators, representatives in Congress and members of Trump's previous administration at the convention.

People are talking about things that matter to them "that are not related exclusively to who they have nominated for their presidential candidate," she said.

"Fundamentally, Americans who are elected to represent their people want to make sure that they are prosperous, that they are safe, that they have a future, that their children have a future -- and their relationship with Canada is a real contributor to those goals."

Vince, who did not want to give his last name, travelled from Illinois to show his support for the Republican leader and said his late wife used to work for Air Canada.

He said he thinks Trump recognizes the special relationship with Canada.

"We are neighbours," Vince said.

"You wouldn't know if there wasn't borders, you would never know what side of the border you're on. We're all the same."

This report by The Canadian Press was first published July 18, 2024.

With files from The Associated Press and Lyndsay Armstrong in Halifax