WASHINGTON - Beijing rejected a request for a secure call between Pentagon chief Lloyd Austin and his Chinese counterpart on the day an American warplane shot down a suspected Chinese surveillance balloon, a US Department of Defence (DOD) spokesman said on Tuesday.

“On Saturday, Feb 4, immediately after taking action to down the PRC balloon, the DOD submitted a request for a secure call between Secretary Austin and PRC Minister of National Defence Wei Fenghe,” Brigadier-General Pat Ryder said in a statement, referring to the People’s Republic of China.

“Unfortunately, the PRC has declined our request. Our commitment to open lines of communication will continue,” he added.

China says the balloon was an errant weather observation aircraft with no military purpose, but Washington has described it as a sophisticated high-altitude spying vehicle.

After slowly traversing the middle of the United States, reportedly over several top-secret military sites, the balloon headed out over the east coast, where a fighter plane shot it down on Saturday.

Mr Austin and General Wei met in Cambodia last November, as Washington and Beijing sought to lower temperatures after a visit by then House Speaker Nancy Pelosi to Taiwan that enraged China.

But the balloon incident has heightened tensions, and led US Secretary of State Antony Blinken to scrap a rare trip to Beijing.

On Monday, President Joe Biden defended the decision to wait until the balloon had crossed the country to down it, saying that the DOD concluded it was best to do so over water.

National Security Council spokesman John Kirby said the same day that measures were taken to ensure the balloon’s instruments were “mitigated” in their ability to spy during the flyover, while “at the same time increasing and improving our ability to collect intelligence and information from it”.

General Glen VanHerck, head of the US Northern Command, said a naval ship would map the debris field left by the balloon, which is expected to measure about 1,500m by 1,500m in the Atlantic.

The balloon itself was up to around 60m tall and carried a payload weighing “in excess of a couple thousand pounds“ that was roughly the size of a regional jet aircraft, he said.

Gen VanHerck said the balloon debris would be carefully studied.

“I don’t know where the debris is going to go for a final analysis, but I will tell you that certainly the intel community, along with the law enforcement community... will take a good look at it,” he said. AFP