The difference being that it's not the U.S. govt that owns the China debt, it's American citizens (heirs of the investors who bought the Chinese railroad bonds a century ago).
In 2024, that number is in the $800-$850 billion range.
They have been cutting back for two years.
Comically, they were being paid less than 1% (annually) on most of their USA debt when they decided to cut back.
Today, a 28-day USA Treasury Bill is paying 5.4% (annually)!