The Foreign Ministry will request a larger budget for fiscal 2015 due in part to costs to open 15 new diplomatic offices abroad, according to government sources.
The ministry is expected to request about ¥738 billion for the year starting next April, up 11 percent from this year, the sources said.
The annual request will include expenses to establish facilities in major countries to deepen understanding of Japanese territory and historical issues, and of Japanese culture.
It will be the first time in eight years for the Foreign Ministry to seek funding to establish more than 10 diplomatic missions abroad.
The ministry wants to open nine new embassies in countries such as Turkmenistan and Albania, and six consulates, including one in Hamburg, Germany.
Japan currently has around 200 diplomatic outposts.
The Foreign Ministry plans to increase its workforce by around 110 from the current 5,787, and to expand hiring of local staff at diplomatic facilities.
The ministry will seek money to increase subsidies for Japanese think tanks, and for expenses for cultural exchange events in a bid to strengthen its public relations activities.