(NewsNation) — White House National Security Council spokesperson John Kirby said the U.S. is continuing to monitor the skies after three unidentified aerial objects were shot down over the weekend.

The influx of objects comes after the U.S. shot down a suspected Chinese spy balloon on Feb. 4. The Navy has been retrieving debris from that balloon for examination, which the Chinese government continues to insist was a civilian meteorological balloon.

China has denied any involvement with the latest three objects and many questions remain about the nature of the objects.

Kirby said the Biden administration began a review of China’s intelligence program when he took office, and determined the country has a high-altitude balloon program, which had also been operating under the previous administration.

Kirby described the benefit of the program as “limited” currently, though he acknowledged advances in technology could make it more valuable. Possible benefits include better quality of images as compared to a satellite and the ability to hover and maneuver to gain more information.

While Kirby said there are other entities that could operate high-altitude objects for a variety of purposes, because the most recent objects were not definitively identified, officials acted with an abundance of caution to protect national security.

Currently, Kirby said there is no reason to suspect the objects were conducting surveillance but it couldn’t be ruled out, and that they were also operating an altitude that posed a risk to civilian aircraft.

“There are no active tracks today,” Kirby said, but NORAD will continue to monitor for other unidentified aerial phenomenon and brief state and federal lawmakers on the issue.

He attributed the increase in objects to adjusted radar parameters meant to detect slower moving objects at higher altitudes with smaller radar cross-sections.

Kirby announced the president ordered an inter-agency team to study aerial objects that could pose a safety or security risk.

When asked if the public could expect to see more incidents of objects shot down, Kirby refused to speculate on the future, saying that the president would work with military leaders to determine if an object posed a risk to safety and security and needed to be downed.

On Friday, the U.S. government downed a flying object over the remote northern coast of Alaska, which was described as cylindrical and a type of airship.

On Saturday, another object was shot down in Canadian airspace, by a U.S. jet, approximately 100 miles from the Canada-U.S. border in the central Yukon. U.S. officials described it as a balloon significantly smaller than the balloon shot down earlier in the month.

Then on Sunday, another object was downed over Lake Huron. It was first detected on Saturday evening over Montana, but it was initially thought to be an anomaly. Radar picked it up again Sunday hovering over the Upper Peninsula of Michigan before bringing it down.

U.S. authorities have made clear that they constantly monitor for unknown radar blips, and it is not unusual to shut down airspace as a precaution to evaluate them. But the unusually assertive response was raising questions about whether such use of force was warranted, particularly as administration officials said the objects were not of great national security concern and the downings were just out of caution.

VanHerck said the U.S. adjusted its radar so it could track slower objects. “With some adjustments, we’ve been able to get a better categorization of radar tracks now,” he said, “and that’s why I think you’re seeing these, plus there’s a heightened alert to look for this information.”

He added: “I believe this is the first time within United States or American airspace that NORAD or United States Northern Command has taken kinetic action against an airborne object.”

Asked if officials have ruled out extraterrestrials, VanHerck said, “I haven’t ruled out anything at this point.”

However, in a briefing, White House Press Secretary Karine Jean-Pierre said there is no evidence that the objects are extraterrestrial in nature. Kirby also stressed that there was no need for the American people to worry about aliens with these objects.

The Associated Press contributed to this report.