As the US was getting ready for the new Kennedy administration, President Eisenhower decided to close the US embassy in Havana and terminate diplomatic relations with Cuba;
“In the climax of deteriorating relations between the United States and Fidel Castro‘s government in Cuba, President Dwight D. Eisenhower closes the American embassy in Havana and severs diplomatic relations.
The action signaled that the United States was prepared to take extreme measures to oppose Castro’s regime, which U.S. officials worried was a beachhead of communism in the western hemisphere.
The immediate reason cited for the break was Castro’s demand that the U.S. embassy staff be reduced, which followed heated accusations from the Cuban government that America was using the embassy as a base for spies.
Relations between the United States and Cuba had been steadily declining since Castro seized power in early 1959.
U.S. officials were soon convinced that Castro’s government was too anti-American to be trusted, and they feared that he might lead Cuba into the communist bloc.
Early in 1960, following Castro’s decision to sign a trade treaty with the Soviet Union, the Eisenhower administration began financing and training a group of Cuban exiles to overthrow the Cuban leader. Castro responded by increasing his program of nationalizing foreign property and companies.
In return, the United States began to implement cutbacks in trade with Cuba. The diplomatic break on January 3, 1961 was the culmination of an increasingly acrimonious situation.”
About 90 days later, The Bay of Pigs happened and we know the rest of that story!