The perils of America's fractured, partisan approach to the COVID-19 pandemic finally caught up Friday with U.S. President Donald Trump, now infected with the very virus that for months has threatened to end his tumultuous tenure in the White House.

Trump delivered the news via Twitter early Friday morning, saying both he and wife Melania had tested positive ⏤ a revelation greeted around the world with shock if not surprise, given the president's apparent disdain for basic precautions.

World leaders responded with a tide of best wishes and speedy-recovery sentiments, an about-face from the angst that greeted Trump's explosive debate performance just four days ago.

The diagnosis, doubtless a major setback for Trump's scramble to catch Democrat challenger Joe Biden before the Nov. 3 election, offers a dramatic reminder about the risks of campaigning during a pandemic.

"Obviously, there is an election going on in the United States where the stances or approaches on COVID-19 have been a polarized political issue," said Prime Minister Justin Trudeau, urging Trump and Melania to get well quickly.

"In Canada, we've been extremely lucky that it has not ⏤ that there has been a concerted effort, across orders of government, across political parties, to work together to be there for Canadians and to get this virus under control.

"We're certainly going to continue with that in Canada," he added, "and we recommend it as a path for people all around the world."

The president and Melania are both experiencing "mild symptoms," said White House chief of staff Mark Meadows, himself having tested negative, as a frenzied cascade of impromptu contact-tracing efforts unspooled on cable news networks.

Friday's news came hours after the White House confirmed that Hope Hicks, one of the president's closest and most trusted advisers, had tested positive for COVID-19 after several days spent travelling in close quarters with the commander-in-chief.

With Trump in quarantine, Monday's vice-presidential debate between Pence and Biden running mate Sen. Kamala Harris will now surely be seen in a different, more urgent light, said former Ohio state senator Capri Cafaro.

As the supper hour approached, following reports that Trump's "mild symptoms" included a fever, the Sikorsky Sea King helicopter designated Marine One was parked on the south lawn, waiting to transport the president to Walter Reed National Military Medical Center.

"President Trump remains in good spirits, has mild symptoms, and has been working throughout the day," press secretary Kayleigh McEnany said in a statement.

"Out of an abundance of caution, and at the recommendation of his physician and medical experts, the president will be working from the presidential offices at Walter Reed for the next few days."

Leaders in B.C. and Saskatchewan, two provinces embroiled in election campaigns of their own, sought to demonstrate Friday that the democratic process can indeed unfold safely, albeit differently, amid COVID-19.

Campaigning can be done "without the glitz and the glamour of big rallies and people waving signs, and so on," said B.C. NDP Leader John Horgan.

Horgan's Liberal rival Andrew Wilkinson said he has been plying the campaign trail in a separate vehicle, and ensures he wears a mask off-camera and that staff members gather only in small groups.

"This is our duty … to make sure that we are maintaining a healthy working environment through the campaign," Wilkinson said.

Canada's provincial leaders also have an inherent advantage in terms of scale, said Saskatchewan Party Leader Scott Moe.

"We are in a truck, not in a plane. We are staying in one province, not travelling across the nation," he said.

"We are not holding large rallies, we are limiting the number of people at each of our events and we are physically distancing, as you can see at each of our events."

With the virus inside the West Wing's perimeter, the day-to-day operations of the Trump administration writ large will also be tested, said Brett Bruen, a consultant and former U.S. diplomat who worked as an adviser in the Obama White House.

"There is a serious risk right now of having a significant portion of the White House staff and the staff of the National Security Council off the field," Bruen said.

"That also raises a lot of serious questions about the leadership of the United States and the dangers for our country."

Vice-President Mike Pence, who would be first in line to take over on an acting basis should the president be unable to discharge his duties, has tested negative, along with his wife Karen.

With Trump in quarantine, Monday's vice-presidential debate between Pence and Biden running mate Sen. Kamala Harris will now surely be seen in a different, more urgent light, said former Ohio state senator Capri Cafaro.

"People always say vice-presidential picks are often chosen for political purposes or for calculus on the Electoral College," said Cafaro, who's now executive in residence at the American University School of Public Affairs in Washington, D.C.

"This vice-presidential debate is absolutely going to be seen as, 'Is this undercard debate really the main event.'"

Ontario Premier Doug Ford, whose perspective on Trump has evolved from largely supportive to sternly critical over the course of the pandemic, joined the chorus of well-wishers as only he can.

"Everyone knows I've had my differences with President Trump; I've called him out, but believe me, I wouldn't want this to happen to my worst enemy," Ford said.

"We may have our political differences, but it's no time — let's put it aside."

This report by The Canadian Press was first published Oct. 2, 2020.

⏤ With files from Kelly Geraldine Malone in Moose Jaw, Sask., Amy Smart in Squamish, B.C., Elizabeth Leighton in Vancouver and Shawn Jeffords in Toronto.