A top U.S. envoy began a two-day trip to Vietnam on Monday to gauge its progress in human rights, two weeks ahead of a visit by President Barack Obama in what will be the first by a U.S. leader in a decade.
Tom Malinowski, assistant secretary of state for democracy, human rights and labor, is expected to press Vietnam to release unconditionally political prisoners and reform its laws to comply with its international commitments.
Relations between the United States and Vietnam have moved to a new level in the past two years as Washington seeks to make a new ally in Asia, but the communist nation's zero-tolerance approach to its detractors remains a sticking point.
Vietnam has jailed dissidents, bloggers and religious figures in recent years, holding them for long periods without access to family or legal counsel and often subject to torture or other mistreatment, according to the New York-based Human Rights Watch.
The United States has been intensifying efforts in building stronger ties - in health, education, environment, energy and recently military - to boost its influence, and offset that of China.
The United States and Vietnam, along with 10 others, this year signed Trans-Pacific Partnership (TPP), one of the world's biggest multinational trade deals.
Though the TPP has no requirements for members to reach certain standards in human rights, analysts say Vietnam's record of arrests, intimidation and oppression of those who speak out against the ruling Communist Party could add to anticipated resistance to the pact among U.S. legislators.
The TPP must be ratified by each member country's parliament.
Malinowski said during his visit to Vietnam last year that he had seen signs of progress on human rights but the country needed to make a stronger commitment.
Rights groups, however, say those improvements might be short-lived and designed to ensure its smooth accession to multilateral trade agreements, including a pact with the European Union.