Koizumi, who leaves office next month, will hold summit meetings with Presidents Islam Karimov of Uzbekistan and Nursultan Nazarbayev of Kazakhstan during his four-day trip to the two countries starting Monday.

The visit, the first by any Japanese prime minister to the region, comes as Tokyo looks to bolster cooperation with the oil- and gas-rich nations to compete with the booming Chinese economy for regional energy resources.

Japan relies heavily on foreign energy and imports nearly all of its oil, mostly from members of the Organisation of Petroleum Exporting Countries (OPEC) in the volatile Middle East, such as Iran.

"Non-OPEC, non-Middle East oil producers are important for Japan's energy security," a senior government official said on condition of anonymity.

"In addition, deterring terrorism from spreading northwards to central Asia from Afghanistan is essential for the security of Japan and the world," he added.

In Kazakhstan, Koizumi and Nazarbayev will announce an agreement to send Japanese experts to help develop Kazakh nuclear power plants, Nobutaka Takeo, an official at the Ministry of Economy, Trade and Industry, told AFP.

Beyond the energy issue, talks in Uzbekistan will focus on the need for democratization and respect of human rights, another senior official at Japan's foreign ministry said on condition of anonymity.