United States naturalization is the process by which a citizen of a foreign country obtains U.S. citizenship and becomes a naturalized citizen of the United States. When applying for naturalization, the United States does not require giving up or losing the original citizenship in order to become a U.S. citizen. As far as the U.S. concerns dual citizens can keep their original citizenship and still become American.
However, is possible that the other country of citizenship will not allow you to have double citizenship. If you have another citizenship and are becoming the U.S. naturalized, it is recommended to find out with the authorities of the country of your second citizenship if dual citizenship or nationality is permissible under their local law.
U.S. law does not mention dual citizenship or requires a person to choose between foreign citizenship and U.S. citizenship. The U.S. government recognizes the existence of dual citizenship and permits Americans to have other nationalities besides their United States citizenship; however, the government does not endorse or encourage dual citizenship because of the problems which it may cause. A U.S. citizen may acquire foreign citizenship by marriage or automatically when born, also the U.S. naturalized citizen may keep the citizenship of the country of birth and become a dual citizen. Dual nationality can also occur when a person is naturalized in a foreign country without intending to relinquish U.S. nationality and thereafter is found not to have lost his U.S. citizenship.
Even if dual citizenship is not unlawful, there are certain acts that may potentially cause the loss of U.S. citizenship. A person who is automatically granted another citizenship does not risk losing his U.S. citizenship.
However, a person who acquires a foreign citizenship by applying for it, voluntarily, by free choice, and with the intention to give up U.S. citizenship, may lose his U.S. citizenship. The intent to give up U.S. citizenship can be shown by the person’s statements or conduct. U.S. citizens are subject to loss of citizenship if they perform certain acts voluntarily and with the intention to relinquish U.S. citizenship.
The U.S. Department of State is responsible for determining the citizenship status of a person located outside of the United States, or when applying for a U.S. passport while in the United States or abroad. Americans can apply to renounce to U.S. citizenship at U.S. embassies and consulates abroad.