That's more than 2006's highly successful Diamond and Pearl versions, which between them sold 1.58 million in their opening weekend, according to a Japanese-language report translated by consumer weblog Kotaku. IGN also reported that this makes Black and White the fastest titles for the DS platform to reach one million consumer preorders.
Pokemon Black and White saw nearly that figure just in Japanese preorders, which reached 1.5 million units leading up to its September 18 launch date in the region. The game reaches Western shores in Spring 2011.
Diamond and Pearl have sold some 18 million life-to-date units, while the subsequent Heartgold and SoulSilver, which came equipped with a "Pokewalker" pedometer, have combined for over 10 million units.
In Japan, Black and White, which represent the fifth generation of Pokemon games, launched alongside the animated Phantom Ruler: Zoroark film, which introduced the title's 150 new Pokemon for the first time.
The games also drew press attention recently for being the most visible example yet of a DSi region-locked title (Japanese releases will not play on DSi hardware from other regions), after numerous Western attendees visited Japan for the Tokyo Game Show and attempted to purchase copies of the game to bring home in advance of its Western launch.