My wife is an Argentine and Italian citizen living in Chile (she is a Chilean permanent resident, but not a citizen). She is thinking of traveling to the USA, and we saw that Italy and the USA have a visa waiver program, and that she should get an ESTA (http://www.esta.us/italia.html).

Her question is, though, what documents should she take to the USA apart from her Italian passport? For example, what about her Argentine or Chilean passport or other documents?

My wife is an Argentine and Italian citizen living in Chile (she is a Chilean permanent resident, but not a citizen). She is thinking of traveling to the USA, and we saw that Italy and the USA have a visa waiver program, and that she should get an ESTA (https://esta.cbp.dhs.gov/esta/).

Her question is, though, what documents should she take to the USA apart from her Italian passport? For example, what about her Argentine or Chilean passport or other documents?