Other nations outside of the region and included on the list were Saudi Arabia, Eritrea, Sudan and Iran.

The State Department categorises countries of particular concern as governments "engaged in systematic, ongoing, egregious violations of religious freedoms."

"The real issue is brutal treatment that religious believers face there," says the report.

Vietnam was included for the first time, joining the other three Asian nations which have been on the list for several years, much to the chagrin of their governments.

Under US law, sanctions could be imposed on these countries, but Secretary of State Colin Powell said Washington would use diplomacy with China, Myanmar and Vietnam to prod them to change their policies.

"Let me emphasise that we will continue engaging the countries of particular concern with whom we have bilateral relationships," Powell told reporters.

The Chinese government was accused in the report of repressing Tibetan Buddhists, Uighur Muslims, Catholics faithful to the Vatican, underground Protestants, and the Falungong sect.

Many religious believers in China "are imprisoned for their faith, and others continue to face detention, beatings, torture and the destruction of places of worship," US ambassador for religious freedom John Hanford said.

In Vietnam, at least 45 religious believers remain imprisoned, including members of the Buddhist, Catholic, Protestant, Hoa Hao and Cao Dai faiths, the report said.

The report said Myanmar's military regime "systemically" restricted efforts by Buddhist clergy to promote human rights and political freedom and discouraged or prohibited minority religions from constructing new places of worship.

The report also kept China, Laos, Myanmar, North Korea and Vietnam together with Cuba on the list of "totalitarian regimes" restricting religious freedom, saying they regarded religious groups as enemies of the state.

Pakistan was included in a list of countries with "state hostility towards minority or non-approved religions" while Bangladesh, India, Indonesia and Sri Lanka were categorised as those with "state neglect of societal discrimination against, or persecution of, minority religions."

Brunei and Malaysia were among countries with "discriminatory legislation or policies prejudicial to certain religions."