Here's a "few", you can easily find dozens more if you make even a trivial effort.
Burma - Bangaladesh
China - Vietnam
Albania - Kosovo
Thailand - Cambodia
Bulgaria - Yugoslavia
Ethiopia - Eritrea
Georgia - Azerbaijan
Lebanon - Syria
Niger - Nigeria
India - Pakistan
Peru - Chile
Saudi Arabia - Yemen
Kenya - Somalia
Mauritania - Morocco
Either way Trump and co seem to be proceeding full speed ahead with their plan.
Uh, of those, I notice two that are likely actual current conflicts and might be relevant to your point: India-Pakistan and Burma-Bangladesh. A lot of those seem like old, buried, forgotten border disputes that certainly have nothing to do with any current conflict or of a country trying to prevent any and all migration.
Lol @ Chile-Peru! wtf--do you think the "Pisco Wars" are really that serious?
Edit: "
The Pisco Wars," since you probably don't know anything, including where to even find those two countries on a world map.
SA-Yemen, certainly active
now, because the war was approved by Jared fucking Kushner himself, paid for by you and I. You can thank him for those landmines, I guess.