Warranty terms & conditions usually apply in accordance with statutes etc in the country/region it was purchased in - additional "extended" warranty plans usually contain some aspect addressing 'international'.
Dell do appear to offer a 'warranty transfer' though, meaning you may purchase in X country/region, and transfer your warranty to the applicable warranty for Y country/region. You would need to contact Dell specifically.
I believe there are a couple of 'region specific' models which may not have the ability to be transferred, but for a 'run of the mill' Dell laptop, you likely can.
See...