The US will allow you to maintain dual citizenship, but they don't really like it, and you need to remember to always present yourself as nothing but a US citizen when dealing with the US government (unless specifically asked about other citizenships, like when applying for Federal government security clearance). Always enter the US with a US passport, and don't talk about your other citizenship while doing so. And don't visit a US consulate overseas and show them your non-US passport or talk about your other citizenship.