I never knew of any preliminary movement on the part of this Government to re-establish diplomatic relations with Russia. I saw a report of that kind in the press. I judged it was without foundation. Of course, our diplomatic relations suffer somewhat, I suppose all countries do, from volunteer activities of people without any authority. We have a great deal of that in Europe. There are a great many Americans that go over there that undertake to say and do things that do not represent the position of the American Government and I think oftentimes result in misleading foreign people and foreign governments. I don't have Russia particularly in mind, but all the governments of Europe. That is something over which we have very little control, but something that happens right along. The organization of the American Government is quite different from that of Europe, which probably results in European governments and certainly European people oftentimes being misled.
Source: "The Talkative President: The Off-the-Record Press Conferences of Calvin Coolidge". eds. Howard H. Quint & Robert H. Ferrell. The University Massachusetts Press. 1964.
Calvin Coolidge, Excerpts of the President's News Conference Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/349177