The Biden administration says the U.S. military has not managed to find debris from any of the three objects that were shot down over North America over the last four days.

A week ago, a U.S. military jet shot down a suspected Chinese spy balloon that had been traversing the country for days. President Joe Biden ordered it down after it crossed the coast of South Carolina.

Minimal debris had been found as of Monday as crews battled the weather, WBTW-TV in Myrtle Beach, South Carolina, reported.

National Security Council spokesman John Kirby said what has been collected included “some of the electronics and structures” from the balloon.

Since then, three other unidentified flying objects have been taken out of the sky -- and nothing has been recovered from them, Kirby told reporters on Monday. They are not believed to have been balloons.

The first of those objects was described as "cylindrical" in shape.

It was taken down off the coast of northern Alaska on Friday. No debris has been recovered.

A second object was shot down Saturday over land in the remote Canadian territory of Yukon. Local authorities are still searching for it.

Katie Simpson with the CBC offered an update on the debris for the object in Yukon on Twitter.

NEW: According to Canadian senior government source with direct knowledge of the situation.

-- U.S. forces have taken down another object, this time over Lake Huron
-- object was completely over U.S. airspace at the time
-- Canada had closed its airspace nearby as a precaution

— Katie Simpson (@Katie___Simpson) February 12, 2023

On the Yukon situation:

-- no debris recovered yet
-- debris field area has been narrowed down but no one there yet
-- incredibly remote, rugged territory
-- search is ongoing, could take a while

— Katie Simpson (@Katie___Simpson) February 12, 2023

"This is rugged country for anybody," Yukon Premier Ranj Pillai said Monday during an interview with the Canadian Broadcasting Corp. "Yukoners who have either hiked or hunted in that area would know, there's lots of elevation ... It's big country.

Pillai predicted the effort to find debris from the object might take some time.

A third object was taken out of the sky Sunday over Lake Huron in Michigan. Military Times reported it is thought to have been first spotted over Montana a day earlier.

Kirby told reporters Monday afternoon officials believe the debris ended up on the Canadian side of the lake.

John Kirby says they believe the UFO shot down over Lake Huron yesterday ended up landing on the Canadian side of the lake. Both the US and Canada are trying to recover the debris now but Kirby says it's probably at the bottom of the lake #cdnpoli pic.twitter.com/Z0IZFohwQQ

— Mackenzie Gray (@Gray_Mackenzie) February 13, 2023

The U.S. Coast Guard is working with officials in Canada to find whatever splashed down.

This article appeared originally on The Western Journal.