Baron Carl Gustaf Mannerheim was head of Finland’s military during World War II; from 1941 until 1944 Finland fought alongside Germany against the Soviet Union though not as a formal ally (the “Continuation War” following the Soviets’ victory in the Winter War of 1939-40 after invading Finland–see Finland’s War of Choice: The Troubled German-Finnish Coalition in World War II).
In early June 1942 (some three weeks before the second major German offensive against the Soviets which led to disaster at Stalingrad–Fall Blau in the southern USSR, not the whole front as in June 1941) Hitler visited Finland for Marshal Mannerheim’s birthday. A photo:
The two leaders had a personal conversation on the train (mostly Hitler, natch–but no raving, indeed no loud voice) which was secretly recorded by the Finns, apparently the only such recording of Hitler. Here it is, note Hitler’s emphasis on a possible Soviet threat to Romania, and oil desperately needed by Germany, in the fall of 1940:
Here is a longer version of the recording, with the first part clearly for the broader audience in the rail car. Hitler is full of Scheiße about what he was all about.
As for countries fighting with Hitler more broadly you really should look at Curzio Malaparte’s astonishingly worth the read Kaputt.