Japan's current account surplus shrank by nearly a third to a record low in 2013 as a weak yen bloated the country's post-Fukushima energy bills.
Japan logged a surplus of Y3.31 trillion ($A36.20 billion) on its current account, the smallest on comparable data stretching back to 1985, according to finance ministry data released on Monday.
The current account is the broadest measure of the country's trade with the rest of the world, including not only trade in goods but also services, tourism and returns on the country's foreign investment.
In December alone, Japan posted a current account deficit of Y638.6 billion ($A6.98 billion), a record for a monthly shortfall.
Japan has been saddled with a growing trade imbalance stoked by its heavy dependence on importing pricey fossil fuels to generate electricity with nuclear reactors shut down in response to the 2011 tsunami-sparked atomic disaster.
The yen's sharp depreciation since late 2012 has pushed up import costs.
Japan's trade deficit more than doubled to Y10.6 trillion ($A115.94 billion) in 2013 from the previous year as costlier imports of oil and gas overwhelmed export growth.
