Former Vietnamese premier Phan Van Khai, who helped strengthen ties with the United States and drive market reforms that ignited the communist country’s economy, died on Saturday at the age 84, the government said. A Soviet-trained economist from southern Vietnam, Khai held office for nine years starting in 1997, a period of reform that saw Vietnam transform into one of Southeast Asia’s fastest growing economies. Vietnam’s incumbent leader recently declared a sweeping government overhaul that will slash 400,000 public-sector jobs. But the campaign seems as much about his consolidating power in the one-party state as about righting its finances.