what must an immigrant to the united states agree to before he or she can become a us citizen
Citizenship of the United States U.S. law permits multiple citizenship. A citizen of another country naturalized as a U.S. citizen may retain their previous citizenship, though they must renounce allegiance to the other country. A U.S. citizen retains U.S. citizenship when becoming the citizen of another country, should that country's laws allow it. Citizenship can be renounced by American citizens who also hold another citizenship via a formal procedure at a U.S. Embassy,[8][9] and it can also be restored.[10]