Nokia is back in the USA. The company on Monday unveiled the Nokia Lumia 900, an LTE-capable Windows Phone 7 (WP7) smartphone. The Lumia 900 will launch as an exclusive with AT&T.

Nokia CEO Stephen Elop unveiled the phone during an afternoon press event at the annual CES International show in Las Vegas. Elop took time to outline Nokia’s plans for re-entering the U.S. market, a move that hinges on a tight partnership with AT&T.

The 900 emerges as Nokia’s flagship smartphone here in the United States, following closely in the footsteps of the Lumia 800.  The mid-range Lumia 710 launches with T-Mobile in the United States on Jan. 11, while the Lumia 800 is only available in Europe.

Elop explained that the 900 was “specifically designed for a North American audience.”

The phone features a 4.3-inch clear black AMOLED display, 1830 mAh battey, 1.4 GHz processor and wide-angle front and rear-facing cameras. Elop said the Lumia 900’s lack of NFC was about priorities but added that the feature will most likely be included in future models.

The 900 comes preloaded with apps by CNN, ESPN, as well as a video-calling application from Tango.

Elop acknowledged the need for differentiation amongst the various OEMs creating phones around WP7, but he also stressed that the company is working closely with Microsoft to avoid the kind of fragmentation that has plagued “other platforms.”

“We would not want to introduce APIs that are different on a Lumia than on other Windows phones,” Elop said, adding that differentiation could be created through unique applications and user experience.

When asked whether Nokia would consider developing a tablet, Elop said such a product would depend largely on whether the company could differentiate from other slates on the market.

Microsoft CEO Steve Ballmer was also on hand at the event. He said the partnership with AT&T has been critical to bringing new Nokia smartphones to the United States. He called the Lumia 900 a “very important milestone” in Microsoft’s partnership with Nokia, which was announced early last year.

Elop declined to comment on sales figures of the Lumia 710 and 800 in Europe, and the company is not immediately releasing pricing and availability for the Lumia 900.