Who said, "Mankind must put an end to war, or war will put an end to mankind."?

On September 25, 1961, President John F. Kennedy’s address before the General Assembly of the United Nations in New York City contained the quote “Mankind must put an end to war, or war will put an end to mankind.”

At the start of his speech, President Kennedy notes the recent death of U.N. Secretary-General Dag Hammarskjöld. Then he goes on to discuss how the world must find peace; nations must work as one to make the world a peaceful place. President Kennedy will, at two minutes into his speech, famously state, “Mankind must put an end to war or war will put an end to mankind.” Together historians and political scholars point out that with its simple language and straightforward style, great presidential power has been given to this quote as a message of peace.

President Kennedy next presents six proposals for a new disarmament program. He also provides information on the current crises in Laos, South Vietnam, and Berlin, Germany. Overall, President Kennedy has refused to accept the view that mankind is bound to war and that peace can never be a reality. He seems to have real hope and believes that peace (in the end) will have the final word. He said, "Together we shall save our planet, or together we shall perish in its flames. Save it we can -- and save it we must -- and then shall we earn the eternal thanks of mankind, and, as peacemakers, the eternal blessing of God."