Can I travel on a valid U.S. visa in an expired passport?
Generally yes. If you have a valid U.S. visa in an expired passport, you may still travel to the U.S. on the valid visa, provided you travel with a valid passport of the same nationality as the expired passport and the two passports contain identical biographic data. For this purpose, both British National (Overseas) and Hong Kong SAR passports are considered the same nationality. As such, you may travel on a valid visa in an expired BN(O) passport with a valid HKSAR passport with the same biographical information, or vice versa. If you are traveling on valid visa in an expired passport, please be sure to travel with both the expired passport and the valid passport. Please note, however, that you may not travel on a valid visa in an expired People's Republic of China passport with a valid HKSAR passport, or vice versa, as these two passports are not considered the same nationality for this purpose.
Note that while you are not required to obtain a new U.S. visa in your new passport, you may do so if you like. If you choose to do so, however, you will be making a new application (see "How Do I Apply?").