Do I need to fill out a visa waver travelling to the USA if I am a

[BertPerry]

citizen but don't have a passport? I am a citizen of Australia and the USA and I live in Australia.

I am travelling to the US for a wedding and only have an Australian passport and not an American passport. Do I need to fill out the standard visa waiver that non-citizens of the US need to fill out?
I probably have my social security card somewhere and I definitely have an expired US passport (issued when I was much younger)

 

[BrandonK]

Yes, you are taking the role of a Australian citizen. The visa form will ask what your nationality is. Simply mark US..

 

[Neil]

What proof do you have that you are a U.S. citizen?