[cjrp]

They'll use the same engine, but quite often different engines are available in different territories. I know that the VAG 1.5 TSI (used in lots of cars here) still uses a belt for example, but the 2.0 TSI is chain. Perhaps in America only the 2.0 is available.

[Kon-Peki]

VAG sells the 1.8 TSI in the US in addition to many variations of the 2.0 TSI.

That 1.5 TSI is not really a performance engine and it needs to be as inexpensive as possible. Chains are more expensive than belts.