plan were unacceptable to Tsarapkin, who responded with separate proposals rejected by the Western powers. Specifically, the Soviet Union proposed a "troika" mechanism: a monitoring board composed of representatives of the West, the Soviet Union, and nonaligned states that would require unanimity before acting (effectively giving the Soviet Union veto authority). In May 1961, Kennedy attempted via secret contact between Attorney General Robert F. Kennedy and a Soviet intelligence officer to settle on 15 inspections per year. This was rejected by Khrushchev. Ahead of the June 1961 Vienna summit between Kennedy and Khrushchev, Robert F. Kennedy spoke with the Soviet ambassador to the US, who suggested that progress on a test ban was possible in a direct meeting between the leaders. President Kennedy subsequently announced to the press that he had "strong hopes" for progress on a test ban. In Vienna, Khrushchev suggested that three inspections per year would have to be the limit, as anything more frequent would constitute espionage. Khrushchev privately believed allowing three inspections to be a significant concession to the West, as other Soviet officials preferred an even less intrusive system, and was angered by US resistance. Khrushchev later told his son, "hold out a finger to them—they chop off your whole hand." Additionally, the Soviet Union had once been ready to support an control commission under the aegis of the UN, Khrushchev explained, but it could not longer do so given perceived bias in recent UN action in the Congo. Instead, Khrushchev reiterated the troika proposal. Furthermore, Khrushchev insisted that the test ban be considered in the context of "general and complete disarmament," arguing that a test ban on its own was unimportant; Kennedy said the US could only agree with a guarantee that a disarmament agreement would be reached quickly (the Vienna demands thus amounted to a reversal of both sides' earlier positions). Kennedy also disagreed that a test ban was itself insignificant; the world could expect many more countries in the coming years to cross the nuclear threshold without a test ban. Ultimately, the two leaders left Vienna without clear progress on the subject. The Soviet Union would drop the general-disarmament demand in November 1961. Lifting the moratorium: 1961–1962 Following the setback in Vienna and Berlin Crisis of 1961, as well as the Soviet decision to resume testing in August (attributed by Moscow to a changed international situation and French nuclear tests), Kennedy