The unknown high-altitude object that the U.S. shot down near Alaska on Friday was heading into Canadian airspace, sources tell CTV News.

"The general area would be just off the very, very northeastern part of Alaska, right near the Alaska-Canada border," White House National Security Council spokesperson John Kirby told reporters on Friday. "We're calling this an object, because that's the best description we have right now. We do not know who owns it."

On Friday afternoon, U.S. officials announced that an F-22 fighter jet shot down the object off the coast of Alaska, not far from the Canadian border. The order to shoot it down came directly from U.S. President Joe Biden, just hours after Canadian Defence Minister Anita Anand met with her American counterpart at the Pentagon.

"Today at the Pentagon, United States Secretary of Defense Lloyd J. Austin III and I participated in a call with NORAD Commander, General Glen VanHerck regarding a high-altitude object detected over Alaska," Anand said in a statement to CTV News. "The object did not fly into Canadian airspace. During this conversation, I conveyed Canada’s support for taking action to take down this object. NORAD deployed aircraft to track and monitor the object and provided important information to decision-makers – and the object was taken down earlier today by United States Northern Command."

Roughly the size of a small car, the object was first detected Thursday night. A U.S. source told ABC News it was "cylindrical and silver-ish gray" and appeared to be floating. No details have emerged about its origins and purpose. Travelling at 40,000 feet (12,000 metres) and apparently unmanned and unable to manoeuvre, it was deemed a reasonable safety threat to civilian flights and shot down over the Arctic Ocean.

"Civilian aircraft operate at a variety of ranges, up to 40,000 to 45,000 feet (12,000 to 13,700 metres)," Pentagon press secretary and Air Force Brig. Gen. Pat Ryder told reporters on Friday. "So there was a reasonable concern that this could present a threat or a potential hazard to civilian air traffic."

Recovery efforts are now ongoing at a reportedly frozen stretch of the Beaufort Sea.

"This afternoon, an object that violated American airspace was brought down," Prime Minister Justin Trudeau said in a Tweet Friday evening. "I was briefed on the matter and supported the decision to take action."

The incident follows the Feb. 4 downing of a suspected Chinese spy balloon that spent a week traversing Canada and the U.S.

"I think we shouldn't be concerned," CTV military analyst and retired Canadian Maj.-Gen. David Fraser told CTV News Channel. "The U.S. military and the Canadian military are going to be watching extremely vigilantly, looking for more of these things coming into our airspace and taking them out if they are a threat."

Fellow retired Canadian Maj.-Gen. Denis Thompson expects U.S. officials to remain tight-lipped until they know more about the object.

"What is good to note is that it would have been picked up by Norad's North Warning System, and that's what would have triggered this decision making process that ended up in it being shot down," Thompson told CTV News Channel.

A chain of 52 radar stations stretching 4,800 kilometres from Alaska to Labrador, the 1980s-era North Warning System acts as a "trip wire" for the continent's northern approaches. It's overseen by the North American Aerospace Defence Command, better known as Norad, which is a joint Canada-U.S. defence group.

"But wouldn't it be ironic if this was a Russian balloon that they floated our way just to poke a stick in our eye?" Thompson speculated. "And that's not unusual. Russia has constantly challenged Norad's airspace with their strategic bombers, and they get turned around both by Canadian and American jets on a routine basis. So perhaps that's all it is."

With files from CTV News' Parliamentary Bureau and the Associated Press