Vinegar only kills the foliage. It doesn’t get transported to the root, for a complete kill.

Again, triclopyr....

https://www.homedepot.com/p/Crossbow-32-oz-Concentrate-Brush-and-Weed-Killer-100509322/203070324

It’s pretty safe if used close to other trees (not much spread), but don’t get much on them.