It's been reported that a large hot air balloon, or what looks like it is above the state of Montana and a few others. It's also been ascertained by some officials that it's from China. It may be used for spying, and the Chinese foreign ministry has not denied it's theirs but has been vague about it as well. It floating well up above the country so that it can't be said to be in a prohibited airspace. Also, it's been said that the US won't shoot it down because of the potential harm to people below.
https://www.cnn.com/2023/02/02/politics/us-tracking-china-spy-balloon/index.html