Pentagon spokesperson Brigadier General Pat Ryder said on Thursday that the US was “aware that [the balloon] had intelligence collection capabilities”.

But “it has been our assessment now that it did not collect while it was transiting the United States or over flying the United States”.

He said the efforts the US took to mitigate any intelligence gathering “contributed” to the balloon’s failure to gather sensitive information.

Gen Ryder did not confirm a Wall Street Journal report that American-made equipment was part of the balloon, but he said that Chinese drones in the past have used off-the-shelf US equipment.