The United States has detected what it says is a Chinese surveillance balloon that has been hovering over the northwestern part of the country. The announcement of the discovery by the Pentagon on Thursday came just days before US secretary of state Antony Blinken is due to visit Beijing.

Fighter jets were mobilised but military leaders advised president Joe Biden against shooting the balloon out of the sky for fear debris could pose a safety threat, advice Mr Biden accepted, US officials said.

The US took “custody” of the balloon when it entered US airspace and had observed it with piloted US military aircraft, one of the officials told reporters on condition of anonymity.

Germany’s CDU faces headache over ex-spy chief’s refusal to leave party amid racism claims

---

Mark Paul: Britain’s striking teachers aim to give government a lesson

---

Irish showdown shapes crucial EU climate goals legislation

---

‘Hard cash’: Roberta Metsola on Qatargate and how Ukraine transformed the EU

---

Mr Blinken’s visit is the first to China by a US secretary of state in six years.

US officials said the balloon had travelled from China past the Aleutian Islands of Alaska, and through northwest Canada over recent days few arriving somewhere over Montana where it was hovering on Wednesday.

Separately on Thursday the state department in Washington described the relationship between the US and China as “the most consequential and complex” on the planet.

A state department spokesman said the purpose of high level engagements with China was exclusively the responsible management of this relationship.

Asked at a press briefing whether any visit by the new speaker of the House of Representatives Kevin McCarthy to Taiwan could damage relations with Beijing – similar to a controversy generated by a trip by his predecessor Nancy Pelosi to the island last year – the spokesman said he was unaware that any such plans had been announced.

He said the US was concerned about how China reacted to Ms Pelosi’s visit.

“ In the aftermath of a visit that was not unprecedented the People’s Republic of China ... used that travel as a pretext to intensify what it has been doing over the course of many years now: attempting to erode the status quo, the status quo that has really been at the heart of decades of peace and stability across the Taiwan Strait.”

The spy balloo incident recalls the lengths to which Beijing and Washington have been willing to go to spy on each other amid rising tensions between the superpowers.

“The United States government has detected and is tracking a high-altitude surveillance balloon that is over the continental United States right now,” Pentagon spokesman brigadier general Patrick Ryder told reporters.

“The balloon is currently travelling at an altitude well above commercial air traffic and does not present a military or physical threat to people on the ground.”

Mr Blinken is expected to travel to China at the weekend for a visit agreed to in November by Mr Biden and Chinese president Xi Jinping. It was not clear how the discovery of the spy balloon might affect those plans.

The Chinese foreign ministry did not immediately respond to a Reuters request for comment.

US officials brought up the issue with their Chinese counterparts through diplomatic channels in Beijing and in Washington. “We have communicated to them the seriousness with which we take this issue,” a US official said.

US senator Marco Rubio, the top Republican on the Senate intelligence committee, said the spy balloon was alarming but not surprising.

“The level of espionage aimed at our country by Beijing has grown dramatically more intense and brazen over the last five years,” Mr Rubio said on Twitter.

His fellow Republican, senator Tom Cotton, called for Mr Blinken to cancel his trip.

Republican House speaker Kevin McCarthy said he would request a Gang of Eight briefing, referring to a classified national security briefing for congressional leaders and Republican and Democratic leaders of the intelligence committees. The Biden administration briefed Gang of Eight staff earlier on Thursday and has offered additional briefings, a US official said.

The news broke as CIA director William Burns was speaking at an event at Washington’s Georgetown University, at which he called China the “biggest geopolitical challenge” currently facing the United States.

Relations between China and the United States have soured in recent years, particularly following then-US House speaker Nancy Pelosi’s visit to Taiwan in August, which prompted dramatic Chinese military drills near the self-ruled island.

[ Significant breakthroughs unlikely as Blinken visits Beijing ]

Since then, Washington and Beijing have sought to communicate more frequently and prevent ties from worsening.

US military leaders considered shooting down the balloon over Montana on Wednesday but eventually advised Mr Biden against it because of the safety risk from debris, the official told reporters.

In Billings, Montana, the airport issued a ground stop as the military mobilised assets including F-22 fighter jets in case Mr Biden ordered the balloon be shot down.

“We wanted to make sure we were co-ordinating with civil authorities to empty out the airspace around that potential area,” the official said.

“But even with those protective measures taken, it was the judgment of our military commanders that we didn’t drive the risk down low enough. So we didn’t take the shot.”

[ EU looks to US with goal of depriving China of most advanced technologies ]

The official said the current flight path would carry the balloon over a number of sensitive sites, but did not give details. Malmstrom Air Force Base in Montana is home to 150 intercontinental ballistic missile silos.

A separate US official said the spy balloon had been tracked near the Aleutian Islands and Canada before entering the United States.

Officials declined to say how high the balloon was flying but acknowledged it was operating above civilian air traffic and below “outer space”.

Such balloons typically operate at 80,000-120,000ft, well above where commercial air traffic flies. The highest-performing fighter aircraft typically do not operate above 65,000ft, although spy planes such as the U-2 have a service ceiling of 80,000 feet or more.

Craig Singleton, a China expert of the Foundation for Defence of Democracies, said that such balloons had been widely used by the United States and Soviet Union during the Cold War and are a low-cost intelligence gathering method.

Spy balloons have flown over the United States several times in recent years, but this balloon appeared to be lingering longer than in previous instances, an official said.

“Currently, we assess that this balloon has limited additive value from an intelligence collection perspective, but we are taking steps nevertheless to protect against foreign intelligence collection of sensitive information,” the official said.

[ Philippines grants US expanded access to military bases close to flashpoints involving China ]

Singapore-based security analyst Alexander Neill said while the balloon was likely to provide a fresh irritant to China-U. S. ties, it was probably of limited intelligence value compared to other elements China’s modernising military has at its disposal.

“China has its own constellation of spy and military satellites that are far more important and effective in terms of watching the US, so I think it is a fair assumption that the intelligence gain is not huge,” said Mr Neill, who is an adjunct fellow at Hawaii’s Pacific Forum think-tank. – Additional reporting: Reuters