It lies in which frequencies the carrier you want to use uses. The first SIM card you put into the phone usually locks it to the region, so if you put in aasian card, it'll be locked for use in Asia (southeast or any other part of the continent). The phone has to be SIM-unlocked (what's usully called just "unlocked") so it can take any carrier's SIM. But if the frequencies the carrier uses for data aren't in the phone, you'll get very low speed data (over the voice channel - it's called EDGE). Check the carrier at
List of mobile network operators of the Asia Pacific region - Wikipedia, the free encyclopedia and check the data frequencies they use against the frequencies the phone has - it looks like the 4G (not the 4G 2015) has the following (LATAM is Latin America):
3G bands
HSDPA 850 / 900 / 1900 / 2100
HSDPA 850 / 1700 / 1900 / 2100 - T-Mobile, AT&T
HSDPA 850 / 900 / 1700 / 1900 / 2100 - USA
HSDPA 850 / 1900 / 2100 - LATAM
4G bands
LTE 700 / 850 / 1700 / 1900 (Bands 2, 4, 5, 17) - USA
LTE 800 / 900 / 1800 / 2100 / 2600 (Bands 1, 3, 7, 8, 20) - EU
LTE 700 / 1700 / 2100 / 2600 (Bands 4, 7, 17) - LATAM