[Kurfürst]

The simple answer to that is that in November 1940 Molotov came to Berlin. Hitler suggested that Germany and USSR would divide up the British Empire - Molotov was not interested, and told Hitler in fairly straightforward terms that Soviet-Russia wants Finnland, Rumania, Turkey and Bulgaria. Hitler probably heard that as nickel, oil and chromium... the rest is history.

I highly recommomend Paul Schmidt's book, 'I was Hitler's Interpreter' on the matter, as he was present at the meeting and gives a very detailed account of it.