Brezhnev served as Secretary General of the Soviet Communist Party from 1964 to 1983. He sent his prime minister, Aleksei Kosygin, to Hanoi in 1965 in an attempt to persuade North Vietnam to negotiate with the U.S. The visit was aborted when American bombing of the north began. Despite U.S. demands in 1972 and 1973 that Moscow curb the North Vietnamese from further agressions, Brezhnev always claimed he had no influence on the Asian country.