I suppose my daughter would be considered a dual U.S. - U.K. citizen, born in England while I was serving in the U.S. Air Force, she has a "Certificate of Birth Abroad" issued by the State Department to prove she is a U.S. citizen, and also a British Birt Certificate issued in Lakenheath village, Suffolk.
However, in my view, if she were to run for public office in the U.S., she should denounce her U.K. citizenship.
Renounce, not denounce, but yes.