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:
Warsaw_Pact

Context:
In July 1963 the Mongolian People's Republic asked to join the Warsaw Pact under Article 9 of the treaty. For this purpose a special protocol should have been taken since the text of the treaty applied only to Europe. Due to the emerging Sino-Soviet split, Mongolia remained on observer status. Soviet stationing troops were agreed to stay in Mongolia from 1966.

Question:
In which year did Mongolia seek entry in the Warsaw Pact?

1963