The Pentagon confirmed on Thursday that it was tracking a Chinese spy balloon flying high over the United States, just days ahead of a rare visit to Beijing by the Secretary of State Antony Blinken.

A senior defense official told reporters that at US President Joe Biden's request, Defense Secretary Lloyd Austin and top military officials considered shooting the balloon down but decided that doing so would endanger too many people on the ground.

"Clearly, the intent of this balloon is for surveillance," the official, who spoke on condition of anonymity, considered.

HAPPENING NOW: Photo shows the massive Chinese spy balloon over Montana.

U.S. military is tracking the balloon. pic.twitter.com/RS52mQE9Og

— Antonio Sabato Jr (@AntonioSabatoJr) February 3, 2023

The official indicated that the balloon had flown over the northwest United States, where there are sensitive airbases and strategic nuclear missiles in underground silos, adding that the Pentagon did not believe it constituted a particularly dangerous intelligence threat.

"We assess that this balloon has limited additive value from an intelligence collection perspective," the official said.

The discovery of the aircraft comes just days before an expected visit to China by Blinken, which follows a meeting last November between Biden and Chinese President Xi Jinping on the sidelines of the G20 summit. The visit will be Blinken's first trip to the Asian country since 2018.

Relations between the US and China have deteriorated particularly over Taiwan, with Washington selling arms to Taipei, as Biden has said he would help protect the island in case of an alleged Chinese attack.

The defense official said the balloon entered US airspace "a couple days ago," claiming that American intelligence had been tracking it well before that.

Defense Secretary Lloyd Austin, who was in the Philippines, held discussions on Wednesday with top Pentagon officials after Biden asked about options for dealing with the balloon. Fighter jets were flown to examine it while it was above Montana as discussions took place.

The Pentagon's decision was "not to take kinetic action due to the risk to safety and security of people on the ground from the possible debris field," the defense official said.

On his part, Pentagon Spokesperson Pat Ryder confirmed that the balloon was still being tracked over US airspace.

"The balloon is currently traveling at an altitude well above commercial air traffic. It does not present a military or physical threat to people on the ground," Ryder pointed out in a statement.

According to the senior defense official, China has sent surveillance balloons over the United States in the past, but this one has lingered in US airspace much longer.

"We are taking steps nevertheless to protect against foreign intelligence collection of sensitive information," the official said.

It is noteworthy that Austin was in the Philippines this week to strengthen US defense cooperation, including gaining wider access for Pentagon forces at Philippine military bases.

The defense official said "the seriousness of the issue" with the balloon had been raised with Beijing officials, stressing that "we have made clear we will do whatever is necessary to protect our people in our own land."

Tensions over Taiwan reached a peak last year when Nancy Pelosi, then-speaker of the US House of Representatives, visited the island in a provocative move. After Republicans gained control of the chamber in January, questions have been raised over whether her successor will make a similar trip.

"China’s brazen disregard for U.S. sovereignty is a destabilizing action that must be addressed, and President Biden cannot be silent," current Speaker Kevin McCarthy tweeted Thursday evening.

China’s brazen disregard for U.S. sovereignty is a destabilizing action that must be addressed, and President Biden cannot be silent.

I am requesting a Gang of Eight briefing. https://t.co/KarTCUzbOS

— Kevin McCarthy (@SpeakerMcCarthy) February 3, 2023

Canada says 'potential second incident' linked to spy balloon

On its part, Canada said it was working with the United States to track the surveillance balloon, and it was monitoring a "potential second incident."

"Canadians are safe and Canada is taking steps to ensure the security of its airspace, including the monitoring of a potential second incident," Canada's defense department said in a statement.

"A high-altitude surveillance balloon was detected and its movements are being actively tracked," it added.

The department said that "Canada's intelligence agencies are working with American partners and continue to take all necessary measures to safeguard Canada's sensitive information from foreign intelligence threats."

Read more: Canada plans to increase military presence in Indo-Pacific