Of course it does. The State Department has no choice. It is law. Dual Nationality--A U.S. citizen may acquire foreign citizenship by marriage, or a person naturalized as a U.S. citizen may not lose the citizenship of the country of birth.U.S. law does not mention dual nationality or require a person to choose one citizenship or another. Also, a person who is automatically granted another citizenship does not risk losing U.S. citizenship. However, a person who acquires a foreign citizenship by applying for it may lose U.S. citizenship. In order to lose U.S. citizenship, the law requires that the person must apply for the foreign citizenship voluntarily, by free choice, and with the intention to give up U.S. citizenship.
The U.S. government allows dual citizenship. United States law recognizes U.S. Dual Citizenship, but the U.S. government does not encourage it is as a matter of policy due to the problems that may arise from it. It is important to understand that a foreign citizen does NOT lose his or her citizenship when becoming a U.S. citizen. An individual that becomes a U.S. citizen through naturalization may keep his or her original citizenship. However, as some countries do not recognize dual citizenship, it is important to consider it carefully before applying for U.S. citizenship.
“US law does not mention dual nationality ...”
This is what I meant by my statement that the US does not “recognize” dual citizenship.