BSD equivalent of GNU/Linux cp -rpu ?

[Thomas Mueller]

What is the BSD equivalent of Linux cp -rpu ?

I tried that in FreeBSD, or maybe it was NetBSD, and -u was not recognized.

I think the issue would be differences between GNU/Linux coreutils and util-linux and the BSD counterparts.

the -u flag, for update, means not to copy files that exist in both the source and destination unless the source version is newer.

Idea is to backup a directory, recursively, without copying old files that haven't changed.

Would I use something like rsync or pax ?

Tom