The U.S. has started to recover some parts from the Chinese balloon that an American F-22 fighter jet shot down off the coast of South Carolina, as Biden administration officials said the U.S. was still trying to figure out how much senior leaders in Beijing knew about the alleged spy mission.

Debris from the balloon and its payload was scattered over a patch of about 1.9 square kilometers, and the U.S. is surveying the site as it works to retrieve the wreckage, said Gen. Glen VanHerck, head of NORAD. He told a briefing Monday that one concern for the recovery teams was whether the equipment carried explosives or other hazardous materials.

Asked whether the balloon uproar weakened U.S.-China relations, U.S. President Joe Biden told reporters Monday, "No. We’ve made it clear to China what we’re going to do. They understand our position. We’re not going to back off. We did the right thing. And there’s not a question of weakening or strengthening. It’s just reality.”