The Biden administration is investigating U.F.O. sightings and rebuking China for espionage.
Washington— After the U.S. downed a Chinese spy balloon and three unidentified flying objects over North America a week earlier, the two governments swapped furious allegations over surveillance operations on Monday.

In interviews, U.S. officials said they began following the spy balloon as it set off from Hainan Island in southern China in late January.

https://www.nytimes.com/video/players/offsite/index.html?videoId=100000008769218

Officials claimed military authorities told President Biden that it was probably certainly the same aircraft object that the U.S. had identified twice by Hawaii and over Texas and Florida. On Monday, military officials claimed workers had collected “substantial debris” from the balloon, including “priority sensor and electronics elements,” after a U.S. fighter jet shot it down near South Carolina’s coast on Feb. 4.

It is worsening diplomatically. Wang Wenbin, a Chinese foreign ministry spokesperson, said Monday in Beijing that the US had the “largest spy network in the world” and had violated “the privacy of civilians across the world” by seizing electronic communications.

The White House vehemently denied Mr. Wang’s claim that the US had flown 10 balloons into Chinese territory since last year.

“Any notion that the U.S. government conducts surveillance balloons above the P.R.C. is false,” said National Security Council spokesperson Adrienne Watson.

Ms. Watson said China “to this day has failed to present any convincing reasons for its intrusion into our airspace and the airspace of others” with its spy balloon program.

The acrimonious conversation shows how swiftly the two governments’ intelligence operations are reviving a deteriorating relationship. Since their November meeting in Bali, Indonesia, Mr. Biden and Chinese President Xi Jinping have tried to restore relations, but the spy balloon scandal has derailed their attempts.

The US spies on China extensively. In 2001, a U.S. electronic espionage plane collided with a Chinese fighter jet off China’s coast, killing a Chinese pilot. Huawei, China’s largest telecommunications corporation, was penetrated by the NSA, which followed Chinese military transporting nuclear weapons.

China has long stolen F-35 stealth fighter designs and 22 million Americans’ security clearance information from the Office of Personnel Management.

John F. Kirby, a National Security Council spokesman, said on Monday that he was unaware of any analogous U.S. activity in Chinese airspace.

After the spy balloon incident, any of the three flying objects destroyed in North America from Friday to Sunday being Chinese would be a big provocation. Several U.S. officials emphasised they were not assuming the objects were Chinese surveillance gear.

Mr. Kirby said Monday that Mr. Biden has instructed top national security officials to study how the US patrols its airspace and whether changes are needed.

He said the U.S. military had modified its radar filters to pick up more objects since the spy balloon episode, which could explain the surge of sightings that led to the three shootdowns. Several officials reported that sensor systems are now detecting migrating bird flocks and hang gliders.

White House officials struggled to strike the correct balance between indicating they are on high alert and not alarming over mundane activities. One official stated that NORAD pilots will require updated guidance on when to fire down objects. They rarely fired until this weekend.

“I think we really don’t know right now in terms of whether threshold modifications are needed,” Mr. Kirby said.

Mr. Biden and Canadian Prime Minister Justin Trudeau ordered U.S. fighter jets to shoot down three unidentified objects between Friday and Sunday. Mr. Kirby said debris recovery is continuing at Alaska, Yukon Territory, and Canadian Lake Huron sites.

He added the three objects had no communications signals, no humans inside, and no moving or propulsion capabilities. Mr. Kirby noted that they flew between 20,000 and 40,000 feet, significantly lower than the Chinese surveillance balloon, and may endanger civilian air traffic.

He stated winds pushed the objects west to east.

U.S. officials claimed the octagonal object shot down over Lake Huron after entering Michigan had strings but no payload. They avoided calling the recent three items “balloons.”

Last Monday, the Biden administration accused China of violating sovereignty by sending surveillance balloons over 40 nations on five continents.

On Monday, a senior U.S. official said a suspected high-altitude Chinese surveillance balloon flew near sensitive U.S. military installations in the Middle East last fall, but it was far enough offshore that American officials did not consider it a threat and only monitored it as it transited the region.

The official said the balloon began in or near China and proceeded westward toward the Middle East, the opposite direction of prevailing winds and the spy balloon that was shot down over the Atlantic Ocean, suggesting it had its own propulsion.

The person claimed Asian military authorities watched the balloon until it went west into Middle Eastern airspace, where they passed up surveillance duties to military colleagues there.

In a Monday press conference, Lt. Gen. Alexus Grynkewich, the senior U.S. Air Force commander in the Middle East, mentioned a high-altitude balloon incident in his territory last October. The situation was delicate, thus he withheld specifics.

The general claimed it was never a high enough priority. “We observed.”

China says the balloon shot down by the US and one observed over Latin America last week, which the Pentagon believed was also for spying, were civilian meteorological research or test flights.

Mr. Wang, the foreign ministry spokesman, said Monday that American high-altitude balloons had “illegally flown above China’s airspace” more than 10 times since last year.

China claims extensive territory around Taiwan, the South China Sea, the East China Sea, and the Himalayas, so it was unclear what airspace Mr. Wang was referring to.

America’s most critical intelligence comes from its sophisticated spy satellites, which collect electronic communications and human sources. The US has started rebuilding the C.I.A.’s Chinese spy network after Chinese counterintelligence destroyed it over a decade ago.

The US avoids sending surveillance equipment into foreign airspace, notably China’s advanced air defenses. Sending interceptable craft risks losing capabilities.

U.S. spy planes mostly fly in international airspace outside other countries’ territorial waters.

Former officials say the U.S. has contemplated creating high-altitude surveillance craft for counterterrorism or counternarcotics missions, but Russia and China would swiftly discover and destroy them.

Spy wars between the US and China have been explosive.

In 2014, a Chinese fighter jet flew 30 feet from a U.S. Navy surveillance plane in international airspace off China. The Pentagon spokesman, Mr. Kirby, told reporters the encounter was “very, very close, very threatening.”

“Large-scale, high-frequency close-proximity surveillance by the United States endangers Chinese-U.S. maritime and aviation safety,” said Chinese Ministry of National Defense spokesman Col. Yang Yujun.

In 1974, China shot down a U.S. spy balloon inside its borders, but both governments kept quiet. According to a publication administered by the party school of the central committee of the Chinese Communist Party, China kept the incident a military secret while restoring diplomatic relations with the US after 23 years.

With tensions rising, Secretary of State Antony J. Blinken has not announced when he will reschedule his Beijing trip. He and Wang Yi, China’s top foreign policy official, will attend the Munich Security Conference in Germany on Friday. “There’s no meeting on the books,” State Department spokesperson Ned Price said Monday.