A U.S. report that has criticised Vietnam's human rights record included made up stories and presented a distorted picture, according to the Communist Party mouthpiece Nhan Dan daily.
"The report gave fabricated details about times, people's names and several cases to cheat those who do not have objective information about Vietnam," it said in a long editorial on Wednesday about the U.S. State Department's annual report on human rights.
The two countries have developed closer ties in recent years, after putting the Vietnam War behind them, but Washington regularly criticises Hanoi's human rights record and last year put Vietnam on a list of countries that abuse religious freedoms.
Washington, the editorial said, had a distorted view of human rights in Vietnam, which has been accused of abusing ethnic minorities in the Central Highlands, many of whom are Christian.
Vietnam's "severe violations of religious freedom" have landed it among "Countries of Particular Concern", the State Department said.
It said Vietnam restricted freedom of religion and the operation of religious organisations other than those approved by the government.
"The government failed to issue a nationwide decree banning forced renunciations of faith, did not end the physical abuse of religious believers, continued to hold a significant number of religious prisoners, and although it permitted the re-opening of some churches closed in the Central Highlands in 2001, it refused to allow the re-opening and registration of hundreds of others," the State Department said.
Some improvements in religious freedom were evident, it said. "Some religious leaders expressed cautious optimism about a new Ordinance on Religion that the Government released in November, and in December," it said in the report.
Hanoi says it respects freedom of religion.
Vietnam was also cited for serious human rights abuses having to do with freedom of speech, freedom of the press, freedom of assembly, and freedom of association.
Foreign Ministry spokesman Le Dung called the report biased and said in a statement: "We absolutely reject these wrongful assessments".