PhD in New Zealand and Post-doc in US I have a full-fund offer for PhD in computer science from a university in New Zealand. I know work opportunities in NZ is low after my graduation. I really like to study my PhD in the US, but since US universities need GRE scores, I cannot apply to them. 

Now, I have one question. What do you think if I get my PhD from NZ and then move to US for job, such as postdoc? How much do you think I can find a postdoc after my graduation, considering a solid research record.

Another option is to postpone my application till next year, in order to be prepare for GRE exam, although it is very tough for me now. Is it worth to wait for a further year, in your opinion?

More importantly, is there anyone who have had similar condition, I.e. doing PhD in non-US universities and then moved to the US for an academic job?

Thank you
Yes of course you can move from a PhD in NZ to a postdoc in the USA if you publish good work in good conferences/journals. You could potentially study for part of your NZ PhD in the US on a scholarship such as the Fulbright. If you have a PhD offer in NZ then presumably you have some idea of what subject you'd be researching - does that field excite you? Your decision should be primarily motivated by interest in a particular field of research rather than by country (IMO). 

A PhD in NZ/Australia/UK is much shorter than the US (3-4 years compared to 5-7 years in my field at least) and generally doesn't involve coursework - you'd also be adding an extra year on top of the US timeline to sit the GRE exam. One final comment: that you have a PhD offer from NZ and are considering waiting a year to sit the GRE and do a PhD in US makes me think you aren't that interested in taking the PhD offer in NZ - there are few things in life I would discourage as much as doing a PhD without a passion for the subject.