Kyodo News reported Sunday's announcement called for 91 billion yen ($900.35 million) in fresh aid to Myanmar and the waiver of about 190 billion yen ($1.8 billion) in debts.
The offer is designed to help Myanmar's growth as that country's civilian government, led by President Thein Sein, continues with its democratic reform efforts.
Abe, whose visit to Myanmar was the first such by a Japanese prime minister in 36 years, and Thein Sein said in a joint statement the countries agreed to lay "a new foundation for mutual friendship" by boosting cooperation in economic, political and security areas.
Kyodo said the new aid will include about 51 billion yen in fresh loans to help Myanmar's infrastructure development and up to 40 billion yen in grants and technical assistance.
Of the 51 billion yen, 20 billion will be spent to build infrastructure for the Tilawa special economic zone near Yangon, which will be developed by a Japan-Myanmar joint venture by 2015.
Abe said Japan's public and private sectors would cooperate to support Myanmar's efforts to promote democracy, the rule of law, economic reforms, and national reconciliation between the Myanmar government and ethnic minorities, Kyodo said.
During his visit, Abe also met with opposition leader Aung San Suu Kyi, a Nobel Peace Prize winner who has played a major role in the bringing about the changes in Myanmar (formerly called Burma), which earlier had been under decades of harsh military rule.