Samsung Electronics on Wednesday launched its flagship Galaxy S3 smartphone in the U.S. and Mexico, a spokesman said on Thursday. Events in New York and Mexico City were attended by hundreds of staff of mobile providers, journalists and consumers.

It remains to be seen whether Samsung can turn the tables on its main rival Apple. Samsung topped the global smartphone market in the first quarter with a 30.1 percent share as against Apple's 23.8 percent, but in North America Samsung came second with a 25.9 percent market share behind Apple's 35.7 percent.

Models pose with Galaxy S3 smartphones at the launch in Mexico City on Thursday. /Courtesy of Samsung Electronics

The Galaxy S3 is reported to have racked up more than 9 million pre-orders around the world, and could give Samsung the advantage since Apple has not released a new smartphone this year.

Unprecedentedly, all five major U.S. mobile providers decided to sell the Galaxy S3. AT&T and T-Mobile began selling it on Thursday, and Verizon, Sprint and U.S. Cellular will soon follow suit.

Meanwhile, Samsung is expected to launch the Galaxy S3 in Korea next Monday. It will launch both the 3G and 4G LTE models first, but will not start selling the LTE model until mid-July, the spokesman said.