It should be noted that the Nazis did kill millions of Slavs in addition to Jews. Some of these killings of Slavs are considered to compose part of the Holocaust. The "Aryan" concept was not necessarily based on "white" but on which ethnic groups were considered German or Germanizable by Hitler.

From Ian Kershaw's Stalinism and Nazism: Dictatorships in Comparison:

"The Nazi revolution was broader than just the Holocaust. Its second goal was to eliminate Slavs from central and eastern Europe and to create a Lebensraum for Aryans ... As Bartov (The Eastern Front; Hitler's Army) shows, it barbarised the German armies on the eastern front. Most of their three million men, from generals to ordinary soldiers, helped exterminate captured Slav soldiers and civilians. This was sometimes cold and deliberate murder of individuals (as with Jews), sometimes generalised brutality and neglect ... German soldiers' letters and memoirs reveal their terrible reasoning: Slavs were 'the Asiatic-Bolshevik' horde, an inferior but threatening race."