The decision to add two further races to the now 16-race schedule ensured the future WRC status of the German leg of the championship which had been under threat from the need to bring in Mexico and Japan.
In announcing the expanded race diary, the sport's governing body, the FIA stated that the two new rounds would reflect "the genuinely global status of the championship".
The 2004 season will start as usual in Monte Carlo on January 23 but will end in Australia in November rather than Britain, which moves to a mid-September slot after the Japanese rally.
Commenting on the newly acquired WRC status Juan Suberville, president of the organising committee for Rally Mexico, stated: "There is not really any other way to describe the feeling of pride I have for everyone.
"We have been preparing for this moment for the last five years, working body and soul, and it is the achievement of a lifetime."
Mexico will stage its first WRC rally around the city of Leon from March 12-14.
The World Rally Championship has unveiled its expanded calendar for next year including new races in Mexico and Japan.
