Is it correct and natural to say "a country is closed" meaning it's difficult to get into it?

Question

Is it correct and natural to say a country is closed meaning it's difficult to get into it? For example:

North Korea is one of the most closed countries in the world.

If not, what would a native English speaker say instead?

Answer 1

Closed means:

having or forming a boundary or barrier

Therefore, this definition fits your sentence since there is a barrier to get into the country. As a native speaker, I would use your sentence.

Another option:

North Korea is one of the most inaccessible countries in the world.