I recently was in the US completing some fieldwork for my PhD (interviews and observing meetings etc). I was there for the full 90 days that my VWP ESTA allowed, and left in May. However, There has been unexpected progress in the work I was researching, and I now want to go back in July. This would not be for the full 90 days, more like 6 weeks.
Will I have difficulty getting back in, and would I be likely to be denied entry?
I am from the UK, studying at a UK institution, and will receive no renumeration etc from any organisation in the US.