I am an Australian flying from Australia to the US on a return ticket for a 3 month period and plan to use the ESTA visa waiver to enter. First trip to the US.
My question is: What happens if I decide I want to stay longer than 90 days (my return leg can be changed). Do I need to exit the country (eg. to Mexico/Canada) and then apply for a further (2nd) ESTA to re-enter the US, or can I / do I need to apply for a visa from within the US if I decide to stay past 90 days.
I have tried to research this advice from the ESTA website and even made on line inquiry to the US Visa service desk but they have simply responded it is my decision and closed the inquiry case!!.