The National Security Agency was the only American intelligence agency that was aware that East Germany was to take action to deal with the brain drain problem. On 9 August 1961, the NSA intercepted an advance warning information of the Socialist Unity Party's plan to close the intra-Berlin border between East and West Berlin completely for foot traffic. The interagency intelligence Berlin Watch Committee assessed that this intercept "might be the first step in a plan to close the border." This warning did not reach John F. Kennedy until noon on 13 August 1961, while he was vacationing in his yacht off the Kennedy Compound in Hyannis Port, Massachusetts. While Kennedy was angry that he had no advance warning, he was relieved that the East Germans and the Soviets had only divided Berlin without taking any action against West Berlin's access to the West. However, he denounced the Berlin Wall, whose erection worsened the relations between the United States and the Soviet Union.