WASHINGTON--Tibet's longest-serving political prisoner, freed earlier this year, arrived Saturday in the United States on what he described as an unconditional exit visa, Radio Free Asia (RFA) reports. Tanak Jigme Zangpo, 73, said the United States had prevailed upon China to let him leave the country. No comment was immediately available from the Bush administration, which had raised his case in private talks with the Chinese government in the past. Jigme Zangpo flew into Chicago from Beijing at 4 p.m. local time. He was greeted upon his arrival by a State Department official and a relative who lives in the United States. In an interview, he said that he had left the Tibetan capital, Lhasa, on July 11, and that his first priority was to obtain proper medical treatment. "This time the Chinese did not impose any preconditions for my release and departure," he told RFA's Tibetan service, speaking in the dominant Tibetan dialect, Uke. "They allowed me to go directly, with no special restrictions." "To realize my complete freedom--it's unimaginable," he said. "I am unsure whether I will be able to return to Tibet after my medical treatment here." Jigme Zangpo was freed in April after serving 37 years in Chinese jails and labor camps--making him the longest-serving political prisoner in Tibet. The diplomatic calculations behind his departure from Tibet remain unclear. His initial release came nine years ahead of schedule, on medical parole and under international pressure. "My first priority is my health. The U.S. government got me released to get treatment for my poor health. I have some serious diseases," including a heart ailment, he said. Asked about his future plans, Jigme Zangpo said: "I cannot say for sure what I will do. I will study the situation as it comes. Since I now have complete freedom, I hope to live a better life. It is difficult to say what will happen." The former schoolteacher also thanked Washington and others "who worked for my release," he said. Jigme Zangpo spent 32 years in prison between 1965 and 2002, continuously since 1983 when he was convicted of "spreading and inciting counter-revolutionary propaganda" for pasting posters at Lhasa's Jokhang temple. He also spent five years in a reeducation-through-labor camp. His sentences were extended twice, notably after he shouted "Free Tibet" during the 1991 visit of a Swiss delegation to the notorious Tibet Autonomous Region Prison Number One, or Drapchi Prison. In its 2001 report on human rights around the world, the U.S. State Department asserted that "according to credible reports, Chinese government authorities continued to commit serious human rights abuses in Tibet, including instances of torture, arbitrary arrest, detention without public trial, and lengthy detention of Tibetan nationalists for peacefully expressing their political or religious views." Acting on Mao Zedong's orders, Chinese troops annexed Tibet in 1950. Radio Free Asia (RFA) broadcasts news, information, and cultural programming to Asian listeners who lack regular access to full and balanced reporting in their domestic media. Through its broadcasts and call-in programs, RFA aims to fill a critical gap in the lives of people across Asia--giving them a voice as well as a means of connecting with the world and with one another. Created by Congress in 1994 and incorporated in 1996, RFA currently broadcasts in Burmese, Cantonese, Khmer, Korean, Lao, Mandarin, the Wu dialect, Vietnamese, Tibetan (Uke, Amdo, and Kham), and Uyghur. It adheres to the highest standards of journalism and aims to exemplify accuracy, balance, and fairness in its editorial content.