Hanoi and Washington are engaged in a second round of trade talks after US President Donald Trump threatened a 46 percent levy on Vietnamese goods as part of his global tariff blitz, the industry and trade ministry said in a statement.

Vietnam has the third-biggest trade surplus with the United States of any country after China and Mexico and is anxious to address the trade imbalance to head off the tariff threat.

State-owned Vietnam National Industry and Energy Group (PetroVietnam) signed a memorandum of understanding with US company Westinghouse Electric on nuclear power development, according to a statement by the ministry.

The agreement is focused on energy infrastructure investment models, technology transfer and human resource training, it said.

Nguyen Hong Dien, Vietnam's industry and trade minister, said at a meeting with Westinghouse officials that energy development cooperation would be "an important driving force contributing to balancing bilateral trade between Vietnam and the United States".

The ministry quoted Westinghouse corporate affairs executive vice president Margaret Cosentino as saying the company expressed strong support for Vietnam's plan, while emphasising the importance of long-term energy cooperation.

The Vietnamese team had also entered the second round of trade negotiations on Tuesday, it said.

Both sides "spent time discussing the overall approach to resolve fundamental issues of mutual concern", the statement said.

Vietnam wants to restart nuclear power plans to meet its rapidly expanding energy needs and signed an agreement in January with Russia linked to the Ninh Thuan nuclear power project.

The project, which involves two plants in central Ninh Thuan province with a combined capacity of 4,000 megawatts, was originally to be developed with assistance from Rosatom and the Japanese consortium JINED before plans were scrapped in 2016.