Countries that generally do not allow Dual Citizenship
Albania.
Algeria.
American Samoa.
Angola.
Antigua & Barbuda.
Argentina.
Armenia.
Australia.
People Also Ask
Generally, Spain does not permit dual citizenship with another country other than with Iberian countries. If you obtain Spanish citizenship, you will have to renounce your original nationality. There are exceptions, including Spanish-American countries, Andorra, the Philippines, Equatorial Guinea or Portugal.
Despite Japanese law prohibiting dual or multiple citizenship, it's well known that citizens are often able to quietly retain these statuses due to a lack of official revocation procedure.