You can fly any apropraite US registered airplane anywhere in the world.
If you can find a C-172 with a N# in North Korea for rent, then you can take it flying.
You can also ask a countries government to recogionize your FAA liscense and issue you one of theirs on a temporary or permanante basis.
You can go To Austrailia and ask their government to give you a temporary Austrailain PPL with Inst rating based on your US liscenses. Then you can rent an Aussie airplane and fly it over the great barrier reef.
Wherever you are, you still must follow the basic flight rules of the FAA ANDthe rules of that country re, airspace, operating rules, currency, ect. You can't buzz London down the river Thames in your N# airplane, anymore than a Brit could.
Some countries will look at your liscense and give you 90 temp if you spend 10 minutes filling out a form, others will require some training, or any other red tape they want.
Working for an airline, cargo, charter, ect will probably require a permante liscense in that country. Getting a permanante liscense will require more red tape, and almost certinaly require a checkride of some sort.