Why is this thread still ongoing? If you have US passport and another passport, all you need to provide for GE application and kiosk is US passport. If you want to disclose, be my guest.

As far as CBP is concern your other passport could be lost/expired/destroyed/out of country/foreign citizenship renounced.

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I'm dual national. Other passport/citizenship not declosed to CBP for GE or NEXUS.

When you enter US, the other passport that matters is the one tied to GE.