Any action taken by either side's had the possibility of resulting in a nuclear war between the Soviets and the Americans. As a result, in the summer of 1961, Kennedy met with Khrushchev in Vienna to try to find a solution for the problem of Berlin. Kennedy suggested Khrushchev to remove the Soviet troops, and the American troops would then be removed. However, no solution was found since neither side was ready to make concessions. The conference ended with Khrushchev issuing another ultimatum to the United States that gave six months to get out of Berlin. As a result, Kennedy refused to back down and instead prepared for military action, which led to further military escalation by Khrushchev.