US secretary of state postpones China visit after spy balloon flies over Montana

The US secretary of state, Antony Blinken, has postponed a planned visit to China this weekend after the intrusion of a high-altitude Chinese balloon into US airspace.

China had apologised for the incident, claiming it had been a weather balloon which had been blown off course, but US officials made clear they did not believe that explanation and the Pentagon restated its assessment it was a surveillance aircraft, adding that by midday Friday it had changed course and was over the centre of the country.

Blinken’s trip, due to begin on Friday night, has been put off until circumstances are more “conducive”, US officials said.

“We had a broad, substantive agenda in mind,” a senior state department official said. “We had hoped for constructive engagement on all elements of our bilateral relationship, but this issue would have narrowed that agenda in a way that would have been unhelpful and unconstructive.”

In a telephone call with Wang Yi, China’s top diplomat, Blinken noted Beijing’s regret “but conveyed that this is an irresponsible act and a clear violation of US sovereignty and international law that undermined the purpose of the trip,” a state department statement said.

Channels of communication remained open between the two countries, the official said, stressing that the trip had only been postponed and not cancelled.

Related: Pentagon says it is monitoring Chinese spy balloon spotted flying over US

The balloon caused alarm in the Pentagon, which tracked its progress across Canada as far as Montana, home to some of the country’s nuclear missile force. US defence officials described it as a surveillance balloon. Joe Biden was alerted and asked for military options, but it was decided that shooting it down could pose a threat from falling debris to people on the ground.

Asked about the balloon, the Chinese foreign ministry said on Friday: “The airship is from China. It is a civilian airship used for research, mainly meteorological, purposes. Affected by the Westerlies and with limited self-steering capability, the airship deviated far from its planned course.

“The Chinese side regrets the unintended entry of the airship into US airspace due to force majeure [an unstoppable and unpredictable event],” the Chinese statement said. “The Chinese side will continue communicating with the US side and properly handle this unexpected situation caused by force majeure.”

Asked about the Chinese weather balloon explanation, the Pentagon spokesman, Brig Gen Pat Ryder, said: “We are aware of the PRC [People’s Republic of China] statement. However, the fact is we know that it’s a surveillance balloon.”

Ryder said the balloon had “the ability to maneuver”, and was moving eastwards at an altitude of 60,000ft, reaching the centre of the continental United States by Friday midday, but did not specify exactly where it was.

“The balloon has changed its course, which is again why we’re monitoring it, but that’s about as specific as I can get,” Ryder said.

There were reported sightings over Kansas City, and elsewhere in north-west Missouri. Ryder estimated it would remain over the US for a few more days.

“We acknowledge that China has issued this statement of regret,” a senior state department official said. “At the same time, we remain confident in our assessment and our concerns about this clear violation of our sovereignty and airspace remain.

“I’m also confident we’ll continue to maintain constant contact with our Chinese counterparts as we work to manage this in the most responsible and expeditious fashion possible,” the official said.

Chinese state media had earlier used the incident to taunt the US.

“The balloon itself is a big target,” the state-backed nationalistic tabloid the Global Times wrote in English on Twitter, which is banned in China. “If balloons from other countries could really enter continental US smoothly, or even enter the sky over certain states, it only proves that the US’s air defence system is completely a decoration and cannot be trusted.”

Canada’s national defence department said it too had detected a high-altitude surveillance balloon and was “monitoring a potential second incident”. US officials said earlier that the balloon had travelled over part of Canada on its way to Montana.

Canada’s defence authorities made clear there was no public danger, adding: “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.”

The Canadian government summoned China’s ambassador on Thursday to explain the incident, the foreign ministry in Ottawa said.

While flying high over Montana, the balloon caused a temporary suspension of air traffic at the Billings airport. The Pentagon issued a statement to reassure the public, revealing it was not the first such incident.

“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 Pentagon statement said. “Instances of this kind of balloon activity have been observed previously over the past several years. Once the balloon was detected, the US government acted immediately to protect against the collection of sensitive information.”

The postponement of Blinken’s trip will set back efforts to resolve several points of friction, particularly over the future of Taiwan, and each side’s military posture in the Indo-Pacific. Beijing this week strenuously objected to a deal between the Philippines and the US in which Manila has granted the US expanded access to its military bases. Under the deal, the US will have additional access to Philippine bases for joint training, storing equipment and supplies, and building facilities, though not to establish a permanent presence.