It allows it but does not recognize the foreign citizenship(s) of a Mexican national.
This means that you should enter and leave Mexico using your Mexican passport and, while in Mexico, you are not allowed to seek consular assistance from your other country(ies) of citizenship if you get in trouble.
Yes, Thailand allows dual citizenship.
Yes, Venezuela allows dual citizenship.
Yes, Poland allows dual citizenship.
Yes, Uruguay allows dual citizenship, meaning individuals can hold citizenship in Uruguay and another country simultaneously.
Israel allows dual citizenship for those who immigrate to Israel based on Law of Return (aliyah): you have to be Jewish to qualify to hold dual citizenship in Israel.
Yes, New Zealand allows dual citizenship, meaning individuals can hold citizenship of New Zealand and another country at the same time.
yes.the new constitution allows one to have dual citizenship
The British government allows dual citizenship. However, the government of the other country might not allow this thus force you to renounce British citizenship if you want to become a citizen of their country.
Yes, El Salvador allows dual citizenship. Just renew your Salvadoran passport, if you haven't, and you are good to go.
Yes, Kenya allows dual citizenship for its citizens since August 2010. This means individuals can hold citizenship in Kenya along with another country without having to renounce either.
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Well, Peru itself allows dual citizenship. But each case depends on where you are from. Your native country may not allow you to hold your nationality after you become a citizen of another country.