Citizenship of the United States
A person who is considered a citizen by more than one nation has "dual citizenship". It is possible for a United States citizen to have dual citizenship; this can be achieved in various ways, such as by birth in the United States to a parent who is a citizen of a foreign country (or in certain circumstances the foreign nationality may be transmitted even by a grandparent) by birth in another country to a parent(s) who is/are a United States citizen/s, or by having parents who are citizens of different countries. Anyone who becomes a naturalized U.S. citizen is required to renounce any prior "allegiance" to other countries during the naturalization ceremony; however, this renunciation of allegiance renunciation of citizenship to those countries.
Nationality law of the Federated States of Micronesia
Article III, Section 3 of the Constitution, as well as 7 FSMC § 201, prohibit dual citizenship, stating that "A citizen of the Federated States of Micronesia who is recognized as a citizen of another nation shall, within 3 years of his 18th birthday, or within 3 years of the effective date of this Constitution, whichever is later, register his intent to remain a citizen of the Federated States and renounce his citizenship of another nation. If he fails to comply with this Section, he becomes a national of the Federated States of Micronesia."