I’m going to be citing a lot of quotations from this book: A Calculated Risk: The U.S. Decision to Recognize Israel, by longtime State Department officer Evan Wilson, who died in 1984. Wilson found the following quotation in government records from 1945.
"President [Roosevelt] told [mideast envoy Lt. Col. Harold] Hoskins that he ‘fully agreed that a Jewish state in Palestine could be installed and maintained only by force.’"
Roosevelt made the statement a month before he died, post-Yalta, when he was determined to create a "trusteeship" in Palestine that would give rights to Jews and Arabs. FDR had lately met Saudi King Ibn Saud–and been struck by vehement Arab opposition to the idea of a Jewish state.
Indeed, Roosevelt said to Congress, “I learned more about the whole problem, the Moslem problem, the Jewish problem, by talking with Ibn Saud for five minutes than I could have learned in the exchange of two or three dozen letters.” The "injudicious" statement caused "an uproar in Zionist circles," Wilson reports. "Rabbi [Stephen] Wise asked for an early interview with the President."