Ho Chi Minh also had good relations with the US, but Roosevelt was more committed to decolonization than Truman was. Truman was persuaded to essentially stay out of it by Churchill and de Gaulle. The Brits did send assistance right after the surrender of the Japanese in the form of a Gurkha unit to help secure Indochina until French Forces could get there...they rearmed Japanese troops to keep Ho Chi Minh from taking over.

At the same time, there was an OSS team on site that advised the Viet Minh and it didn't end well once the hostilities started. Until that point, we were pretty cordial with the Viet Minh.

I've done some extensive reading of sources on that, particularly Bernard Fall's books, which are interesting and instructive. The American war in Vietnam was very much an extension of the French one, particularly as Eisenhower was roped into increasing support for the French Forces in Indochina in return for concessions from the French in Europe (staying in NATO, for example.)