It seems the US will get the current 1.4 Multiair, with 105hp, and the usual belt cam.
It's being built in Mexico - the car - the engine is being built in the US.
The new Twinair 0.9 engine has a chain, and Fiat is saying that it MAY come to the US later. They are concerned that the Americans will dismiss a small twin cylinder engine, even if it delivers the same power, better torque, and much better economy.