Foreign races (German: Fremdvölkische) was a term used during the Nazi era, the term was meant to describe people who were not of "German or related blood" (Nuremberg Laws). The term at first was used only by members of the SS but then later became used by the state police, justice and administration people.
With the Führerprinzip (leadership principle) of Hitler and the Nazi party supremacy over Germany, the fundamental political life of Nazism was primarily focused on the Aryan race, but also the pan-German nationalism that was to make sure the Germans belonged to the Volksgemeinschaft (national community). The term "foreign" was not used in the term of a migrant but rather racially defined as to who were German citizens but who were not of German or related blood. In 1935 after the Third Reich introduced the Nuremberg race laws, the foreign races who were defined as Jews, Gypsies and blacks were forbid from civil service and sexual relations with Aryans and were given the "non-Aryan" status under these racial laws. Although to be noted, the laws did not just effect people who were not Aryan, but also opponents of the Nazis, who were also stripped from civil service.
With the Nazis policy of Lebensraum (living space) in the East, which called for Germans to settle there and the whole area to undergo a procedure of Germanization for the creation of a Greater Germanic Reich. The people of these areas were targeted as "foreign Nationalists" not "foreign races" since Slavs were not a distinct race, even according to Nazi racial science (Hans F. K. Günther - called - race-Günther - 1930). Thus, the notion of foreign was used not only for people who were classified as racially different but also people who were not part of the German community. In Mein Kampf, Hitler criticized previous Germanization towards ethnic Poles who he regarded as belonging to a "foreign race" to the Germans. In his 1928 unpublished book Zweites Buch, Hitler stated that the Nazis would never Germanize any foreign elements such as the Poles or Czechs as it would lead to a racial weakening of the German people.