Pokemon X & Y, the latest pair of releases in the popular Nintendo RPG series, have sold more than 4 million units since they launches worldwide last week.

This was the first ever Pokemon game to launch on a global scale simultaneously -- Pokemon titles usually launch in Japan first, before hitting Europe and the U.S. months later.

However, Nintendo noted that when the Japanese, U.S. and European launch sales of past Pokemon titles are gathered together, Pokemon X & Y are tracking ahead of the previous titles in the series, Black & White 2, by a notable 70 percent.

Pokemon X & Y are now also the fastest-selling Nintendo 3DS games to date, Nintendo added.

GameFreak's Pokemon franchise has now sold 245 million games worldwide to date, and Nintendo provided additional global sales figures for previous titles in the series, as seen below.

Pokemon Diamond & Pearl - 17.63 million sales
Pokemon Ruby & Sapphire - 16.22 million sales
Pokemon Black & White - 15.42 million sales
Pokemon HeartGold & SoulSilver - 12.67 million sales
Pokemon FireRed & LeafGreen - 12 million sales