The Japanese effort will include $4 billion of low-interest infrastructure loans.
Inaugurating the three-day Tokyo International Conference on African Development, Fukuda said Africa will get a "significant portion" of a $100 million emergency food aid pledge, Kyodo reported.
Japan is seeking to expand its influence in Africa, where China and India have invested heavily. Japan is also wants African nations' support for its effort to reduce global emissions by half by 2050.
"I pledge that by 2012 ... Japan will have doubled its (official development assistance) to Africa," Fukuda said, Kyodo reported.
In his remarks at the conference, World Bank President Robert Zoellick noted the impact of high energy and food prices on Africa and said, "We need to seize the opportunity to expand African agricultural production and productivity."
"We seek the support of the government of Japan to do more to encourage the Japanese private sector to venture into Africa," said Tanzanian President Jakaya Mrisho Kikwete, who is the African Union chairman, the report said.