IIRC 米国 (mi guo / "rice country") is used in Taiwan as well. The other Chinese word for America (美国 / mei guo / "beautiful country") is also a phonetic thing.

(I used to think 美国 was descriptive since it didn't sound phonetic, until I came across 米国 and was confused as to why anyone would describe the US as "rice country", and then I learned that both were phonetic, but for the "me" in "america")