American authorities are still examining the remains of the Chinese spy balloon, which fell into the Atlantic Ocean off the East Coast, while American and Canadian authorities are still trying to reach the remote areas of Alaska, the Yukon Territory and Lake Huron.
The three most recent objects shot down by the Air Force were traveling at heights where commercial aircraft fly. But the spy balloon was higher, at about 60,000 feet. Mark Lewis, the former chief scientist of the Air Force, said that is “a sweet spot” for reconnaissance balloons. “If you look at wind speeds in the atmosphere, there’s kind of a low point in the 60,000- to 65,000-foot range. So it’s kind of a good place to put a balloon.”
Mr. Biden said he had directed Mr. Blinken to work with other countries to establish “common global norms in this largely unregulated space,” presumably referring to the upper atmosphere above the altitude where passenger planes typically fly. American officials have said China has floated spy balloons over 40 countries around the world.
The president said new classified parameters that he has ordered will “guide what action we take while responding to unmanned and unidentified aerial objects.” He promised to share them with Congress but not with the public so as not to give a “road map to our enemies to try to evade our defenses.”
In addition, he said he has directed Jake Sullivan, his national security adviser, to lead a governmentwide effort to address any threat to the airspace by developing a better inventory of unmanned objects above the United States, improving systems to detect them and updating rules and regulations for launching and maintaining such objects.
At times, the government’s existing task force on unidentified aerial phenomena has seemed less than a critical national security effort. But the downing of the spy balloon and the scientific research balloons has infused the work of the task force with additional importance. Some of the priorities that Mr. Biden mentioned on Thursday, like cataloging the inventory of unmanned airborne objects blowing around the skies, are items the task force has already been working on.
Even as he promised action, though, Mr. Biden tried to dispel fears that the threat of surveillance from the skies has grown recently.
“We don’t have a sudden increase of objects in the sky,” he said. “We’re just seeing more of them partially because of the steps we’ve taken to increase our radar, and we have to keep adapting our approach to dealing with these challenges.”
Julian E. Barnes and Edward Wong contributed reporting.
