China said Friday it was working to verify the facts around US claims that Beijing flew a spy balloon over its territory, warning against "hype" over the issue.

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

Chinese Foreign Ministry Spokesperson Mao Ning told a regular briefing that "verification is underway" over the reports, pointing out that "until the facts are clear, making conjectures and hyping up the issue will not help to properly resolve it."

Mao underlined that "China is a responsible country and always abides strictly by international law. We have no intention of violating the territory or airspace of any sovereign country."

"(We) hope that both sides will handle (the situation) with mutual calm and prudence," she expressed. 

A senior defense official told reporters on Thursday 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," claimed the official, who spoke on condition of anonymity.

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.

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

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

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.

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."

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.

At the briefing, Mao said she had no information to share on Blinken's upcoming visit.

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