Washington has accused China of flying a surveillance balloon over sensitive sites ahead of a planned visit by US Secretary of State Antony Blinken to Beijing, with China warning against any "hype" over the issue before verification of facts.
"The United States government has detected and is tracking a high-altitude surveillance balloon that is over the continental United States right now," Pentagon spokesperson Brigadier General Patrick Ryder told reporters on Thursday.
"The balloon is currently traveling at an altitude well above commercial air traffic and does not present a military or physical threat to people on the ground."
The accusation was made after CIA Director William Burns, speaking at an event at Washington’s Georgetown University, described China as the "biggest geopolitical challenge" facing the United States.
Reuters also cited unnamed US officials as saying that a Chinese spy balloon had been flying over the United States for a couple of days.
The United States took "custody" of the balloon when it entered US airspace and had observed it with piloted US military aircraft over Billings, a city in southern Montana, one of the officials was quoted as saying on condition of anonymity.
Reports said fighter jets were mobilized but military leaders advised President Joe Biden against shooting the balloon for fear that debris could pose a safety threat.
Separately, Canada's defense ministry said a "high-altitude surveillance balloon" was detected and that it was monitoring a "potential second incident," without providing further details, adding that it was in frequent contact with the United States.
‘Speculation, hype not to be helpful’
Chinese foreign ministry said Beijing was "verifying" the situation, cautioning against speculation and hype until the facts about the US claims are clarified.
“I would like to emphasize that until the facts are clarified, speculation and hype will not be helpful to the proper resolution of the issue," foreign ministry spokesperson Mao Ning told at a press briefing.
“China is a responsible country that has always strictly abided by international laws, and it has no intention of violating the territory and airspace of any sovereign country. Regarding this balloon issue, as I have just mentioned, we are in the process of understanding and verifying the situation and hope that both sides can handle it together calmly and cautiously," Mao added.
US officials said they had "communicated the seriousness" of the matter with their Chinese counterparts through diplomatic channels.
One US official said the balloon was assessed to have "limited additive value from an intelligence collection perspective."
Blinken is expected to travel to China next week for a visit agreed to in November by Biden and his Chinese President Xi Jinping amid wide-ranging disputes between Washington and Beijing, including the issue of Chinese Taipei.