Note this statement from the iPhone and iPad warranty:
"IMPORTANT RESTRICTION FOR iPHONE AND iPAD SERVICE.
Apple may restrict warranty service for iPhone and iPad to the country where Apple or its Authorized Distributors originally sold the device."*
The above is from the USA version of this iPhone, iPad and iPod warranty document, but this particular section limiting international coverage is much the same for the warranty for all countries. If you wish to check the warranty for where you bought your device, click on this link to take you to the page about Apple warranties, then select your device and country --> Legal - Hardware Warranties - Apple
In fact you may find even if you are prepared to pay for a repair Apple will not repair certain devices (likely anything with cellular capability) from one country in another country. Often Apple does not actually repair a device but simply gives you a refurbished unit that is identical to the one you bought. However, a model from one country may not be available in another.