Documents to that effect were signed on the sidelines of Japanese Prime Minister Junichiro Koizumi's visit to Kazakhstan.
Addressing reporters in Astana, Koizumi described nuclear cooperation with Kazakhstan, including development of uranium fields, as "a promising area."
Kazakh President Nursultan Nazarbaev in turn said his country was interested in attracting Japanese investors. He also described Koizumi's visit as "a new turning point" in the history of bilateral ties.
This is the first time a serving Japanese prime minister visits Central Asia.
Koizumi is expected later this week in neighboring Uzbekistan for talks with President Islam Karimov.
(Kazakhstan Today, Interfax-Kazakhstan)