In a famous exchange at the United Nations, Adlai Stevenson (the American Ambassador) confronts Ambassador Zorin (and his Soviet colleagues) with evidence of a missile buildup in Cuba. On the 25th of October, 1962, the diplomatic approach, between the two countries, hardens.
In one of the most quoted parts of his speech, Stevenson tells Zorin he is "prepared to wait until h___ freezes over" to get a straight answer on the subject.
This Universal Newsreel also provides background on the crisis, including views of the recon planes (and their cameras) which first detected the Soviet missile build-up in Cuba.
Universal Newsreel, 25 October 1962, online courtesy Library of Congress and Archive.org.