Under Hoxha, the party became the most rigidly anti-revisionist party in the Soviet Bloc. In 1961, Hoxha broke with Moscow over Nikita Khrushchev's supposed deviations from fundamental principles of Marxism-Leninism, though relations between Tirana and Moscow had begun to chill as early as 1955. Hoxha opted instead to align with the People's Republic of China under Mao Zedong. In 1968, Albania formally withdrew from the Warsaw Pact. The party even went as far as to engineer an Albanian version of China's Cultural Revolution.