In addition to missing out on Verizon's millions of customers, Samsung also faces other challenges in the U.S. A new iPhone is expected to launch soon, and Microsoft's updated Windows Phone software will be available in the coming months.

However, the Samsung Galaxy S II, first announced in February and already available in much of the world, is proving popular. Five million have been sold in the past 85 days, Samsung said during a press conference on Tuesday.

Samsung initially scheduled the unveiling for Monday in New York but postponed it due to heavy storms. The company is holding a separate event in London on Thursday and has not said what it plans to reveal then.

The IDG News Service