Vietnam granted early release from prison to a Catholic priest who is one of its most prominent dissidents, a move widely seen as a goodwill gesture before President Barack Obama arrives on an official visit late Sunday night. The Catholic Archdiocese of the central city of Hue reported on its webpage that it welcomed the return on Friday of the Rev. Nguyen Van Ly from prison. Photos on its website showed a frail Ly, 70, being helped off a minibus, kneeling to pay his respects to his senior colleagues, then being led to a room prepared for him at the diocese. He has suffered several health crises while imprisoned. Ly has served several long terms in prison or under house arrest for promoting political and religious freedoms in the communist nation. He had been serving an eight-year prison term since March 2007 after being convicted of spreading propaganda against the state. He was first jailed in 1977, two years after the Communist takeover of all Vietnam. Vietnam's persecution of dissidents has been a roadblock to warmer relations with the United States, from which it is seeking the lifting of an arms embargo. Washington and Hanoi share a strategic interest in challenging Chinese territorial claims in the South China Sea, some of which are in areas long claimed by Vietnam. The government's relations have always been strained with the Catholic church, associated with French colonial rule and the former anti-communist South Vietnam, as well as an influential power base independent of the ruling Communist Party's control. The US State Department said it welcomed Ly's release. "We consistently have called for the release of Father Ly and all other prisoners of conscience in Vietnam," said Gabrielle Price, the department's spokeswoman for East Asia and Pacific affairs. "We remain deeply concerned for all prisoners of conscience in Vietnam. We call on the government to release unconditionally all prisoners of conscience and allow all Vietnamese to express their political views peacefully without fear of retribution." More than a dozen human rights groups last month sent an appeal to Obama urging him to press Hanoi to release political prisoners. The appeal, whose signees included Human Rights Watch as well as groups focusing on Vietnam, urged him "to make clear, both in private and in public, that (the) US-Vietnamese relationship will not fundamentally advance absent meaningful human rights improvements, including the release of imprisoned activists, and end to harassment of civil society groups, and respect for international law."