From the fcc report the GSM bands look to only be 850 & 1900. These bands
seem to only be compatible with the Americas.
From wikipedia:
Africa, Europe, Middle East and Asia
In Africa, Europe, Middle East and Asia, most of the providers use 900 MHz and 1800 MHz bands. GSM-900 is most widely used. Fewer operators use DCS-1800 and GSM-1800. A dual-band 900/1800 phone is required to be compatible with almost all operators. At least the GSM-900 band must be supported in order to be compatible with many operators. However, Thailand has also approved for some time now the use of the GSM-1900 band in an attempt to alleviate network congestion.
FCC Information
Also looks like it will not be completely future proof with LTE not capable of running on the soon to be reused IDEN spectrum.