Vietnam's Prime Minister Nguyen Tan Dung arrived in Tokyo Sunday on a four-day visit expected to promote Japan's export of nuclear power plants to his country and joint development of rare earths.

Officials confirmed Dung's arrival and said he was scheduled to attend a dinner with members of the Japanese parliament later in the day, before talks with Japanese Prime Minister Yoshihiko Noda on Monday.

On Tuesday, Dung will tour Japan's northeast coast, hit by the March 11 earthquake and tsunami.

According to Japanese media, Noda is expected to confirm that Japan will help build two nuclear reactors in Vietnam, despite the atomic plant crisis at Fukushima triggered by the March natural disaster.

On a visit to Vietnam a year ago, then Japanese prime minister Naoto Kan announced with Dung that the two countries would join forces in the nuclear reactor project.

Noda and Dung are also expected to reach an agreement on joint development of rare earth minerals in Dong Pao in Vietnam's northwest.

Two Japanese trading houses, Toyota Tsusho and Sojitz, will set up a joint venture with Vietnamese enterprises to start production of the rare earths in 2013, the business daily Nikkei reported last week.

Mines in Dong Pao are rich in such rare earths as lanthanum, cerium and neodymium which are indispensable for production of liquid crystal display panels and motors for gasoline-electricity hybrid vehicles, the daily said.

The two governments will inaugurate a research centre in Hanoi in 2012 to develop technology to separate rare earths from mineral ores and refine them without harming the environment, the Nikkei said.

Accompanied by his wife Tran Thanh Kiem, the Vietnamese premier is also scheduled to call on Emperor Akihito and Empress Michiko at Tokyo's Imperial Palace on Wednesday.