Why can’t a US state default, but a EU state can?

How much do U.S. owe China?

approximately $1.06 trillion

How Much Money Does the U.S. Owe China? The United States owes China approximately $1.06 trillion as of January 2022.

Who owns most of the US debt?

the U.S. government

By far, the largest owner of U.S. debt is actually the U.S. government, which holds Treasury securities in various government accounts and pension funds.