Copyrights can't be renewed in the U.S. either, not today.
Copyrights in the U.S. used to last 28 years. They then could be renewed for a second 28-year period. This changed in the 70's when the U.S entered the Berne Convention. Then things get more complicated...
Works published before 1964, I think, fall under the old rules. Works published after that date have their copyright renewed
automatically.
In the early 90's, congress decided to let people or groups who own works first published outside the U.S. renew U.S. copyrights on works which had already entered the public domain in the U.S, if said work was still copyrighted in their own country. Say you were in Germany in 1950, & you published a book. It was translated & sold in the U.S. in 1951. Twenty years later, the book's gone out-of-print, so you let the U.S. copyright expire. You could, in theory, petition the courts to renew the copyright on your book. However, if you were in the U.S., & you published a book in the U.S. in 1950, & you let the copyright expire, you cannot petition the courts to renew the copyright.
Is that as clear as mud? I'm talking about things which are above my paygrade & outside my field of expertise.
In the late 90's, the U.S. extended their copyright terms, from 50 years after the death of the author, to 70 years. They could've done so again two years ago, but they didn't. My thoughts: by the late 70's & into the late 90's, most works were made by extremely profitable companies, who could lobby to have copyrights extended, & there wasn't a powerful lobbyist group to oppose them. Today there are some major tech companies who make a lot of money by organizing data, not by creating data, so they'd have their own lobbyist groups working to shorten copyright laws. Again, I'm talking about things which are above my paygrade & outside my field of expertise, so take that with a grain of salt, or a whole salt shaker.