President Kennedy signs the Proclamation for Interdiction of the Delivery of Offensive Weapons to Cuba

Only an hour [after Kennedy's address to the nation], at 11:24 a.m. a cable drafted by George Ball to the U.S. Ambassador in Turkey and the U.S. Ambassador to NATO notified them that they were considering making an offer to withdraw missiles from Turkey in exchange for a withdrawal from Cuba. Later, on the morning of October 25, journalist Walter Lippman proposed the same thing in his syndicated column. For many years this has been interpreted as a trial balloon floated by the Kennedy administration, although the historical record suggests this is not the case.

At the time the crisis continued unabated, and that evening TASS reported on an exchange of telegrams between Khrushchev and Bertrand Russell, where Khrushchev warned that the United States' "pirate action" would lead to war. However, this was followed at 9:24 p.m. by a telegram from Khrushchev to Kennedy which was received at 10:52 p.m., in which Khrushchev stated that "if you coolly weigh the situation which has developed, not giving way to passions, you will understand that the Soviet Union cannot fail to reject the arbitrary demands of the United States", and that the Soviet Union views the blockade as "an act of aggression" and their ships will be instructed to ignore it.

On the night of October 23, the Joint Chiefs of Staff instructed Strategic Air Command to go to DEFCON 2, for the only confirmed time in history. The message, and the response, were deliberately transmitted uncoded, unencrypted, in order to allow Soviet intelligence to capture them. Operation Falling Leaves quickly set up three radar bases to watch for missile launches from Cuba.[clarification needed] The radars were experimental models ahead of their time. Each base was connected with a hotline to NORAD control.