You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Space_Race

Context:
On September 20, 1963, in a speech before the United Nations General Assembly, President Kennedy proposed that the United States and the Soviet Union join forces in their efforts to reach the Moon. Soviet Premier Nikita Khrushchev initially rejected Kennedy's proposal.

Question:
When did US President John F. Kennedy, in a speech, propose to join forces to reach the moon with the USSR?

September 20, 1963