The United States will not sell lethal weapons to Vietnam until it reverses the "backward movement" in its human rights situation, US Senators including John McCain said Saturday.
Following a visit to the communist Southeast Asian nation, McCain told reporters in Bangkok that Hanoi had a "long long list" of arms it would like to buy.
But the US delegation "specifically stated to the Vietnamese that our security relationship will be directly impacted by the human rights issues", said McCain, a former prisoner of war in Vietnam.
"There has not been progress on human rights issues, in fact there has been some backward movement on it."
Senator Joe Lieberman added that approval from US Congress was necessary for ally Vietnam to get "lethal" weapons specifically.
"There's certain weapons systems that the Vietnamese would like to buy from us or receive from us and we'd like to be able to transfer these systems to them, but it's not going to happen unless they improve their human rights record," he said.
Rights groups say dozens of peaceful political critics and campaigners have been sentenced to long prison terms since Vietnam launched a crackdown in late 2009, despite Hanoi's stance that its rights record is improving.
Vietnam has been seeking greater exchanges with the United States amid high tensions with China, particularly over disputes in the South China Sea.
The senators spoke ahead of a trip to Myanmar, where they will be looking into dramatic reforms by the nominally civilian government in recent months.
These include the release this month of hundreds of political prisoners, leading US President Barack Obama to call for the resumption of full diplomatic ties.
McCain said US would likely begin to lift sanctions on the country if by-elections held in April were free and fair, but he expressed caution over the pace of change in the country that saw military rule for nearly 50 years.
"It seems to me that we ought to put a pause on things, see what happens and evaluate the situation and then act accordingly. Let's not rush into judgments that we may regret later on," he said.