The US Congress on Thursday began its review of a nuclear agreement with Vietnam which advocates say would create billions of dollars in trade but has triggered human rights concerns.

President Barack Obama sent to Congress the text of the agreement which would allow the United States to transfer reactors and know-how to Vietnam, which has ambitious plans to build a nuclear network from virtually scratch to meet rising energy demand and reignite economic growth.

The agreement will come into force after Congress is in session for 90 working days -- likely meaning late 2014 -- unless lawmakers approve a resolution that objects to the deal.

Vietnam's relations have warmed markedly with former war foe Washington since they re-established relations in 1995. But the US Congress is a hotbed of criticism of the communist nation with lawmakers, often from districts with large Vietnamese American communities, concerned about human rights.

At a hearing on the agreement in January, several senators said that Congress should approve a separate bill on human rights in Vietnam to accompany the nuclear deal. Vietnam has detained at least 34 bloggers, more than any country except China, according to Reporters Without Borders.

The Nuclear Energy Institute, which represents the US industry, has said that the nuclear agreement would advance US interests unrelated to human rights. It said that the deal could result in $10 to $20 billion in new US exports to Vietnam and create more than 50,000 jobs in the United States.

If Congress blocks the agreement, other nations "will readily fill this void" with Russia and Japan already having secured deals with Vietnam, it said.

But some lawmakers who may otherwise be supportive have charged that the Vietnam deal does not meet the "gold standard" of recent deals with the United Arab Emirates and Taiwan which barred them from sensitive enrichment or reprocessing that could be used in producing nuclear weapons.

"The absence of a consistent policy weakens our nuclear nonproliferation efforts and sends a mixed message to those nations we seek to prevent from gaining or enhancing such capability," said Senator Bob Corker, the top Republican on the Senate Foreign Relations Committee.

Obama, in a letter accompanying the agreement, said that Vietnam made a "political commitment" to rely on international markets for nuclear material and not conduct sensitive work on its own.

Vietnam's promise is mentioned in the agreement but it is not legally binding, unlike for Taiwan and the United Arab Emirates -- whose own nuclear energy aspirations are especially sensitive due to Western concerns over neighboring Iran.

Senator Robert Menendez, a member of Obama's Democratic Party who chairs the Senate Foreign Relations Committee, has also raised concern over the timeframe of the agreement, which would run for 30 years and then be renewable for periods of five years, saying that it reduces congressional oversight.

In his letter, Obama said he would make a "strong recommendation" that future administrations consult with Congress on the agreement.