Khrushchev's liberalization of hard-line policies led to an improvement in relations between the Soviet Union and the United States during the late 1950s. As Khrushchev's primary emissary, Mikoyan visited the United States several times. Despite the volatility of the Cold War between the two superpowers, many Americans received Mikoyan amiably, including Minnesota Democrat Hubert Humphrey, who characterized him as someone who showed a "flexibility of attitude" and New York governor Averell Harriman, who described him as a "less rigid" Soviet politician.