The leaders agreed on the need for tough targets to fight climate change
Leaders of Japan and the European Union have called for "highly ambitious and binding" global targets to fight climate change.
Leaders said the G8 summit of rich nations - to be held in Japan in July - must be a real moment of breakthrough on greenhouse gas emissions.
The Kyoto Protocol on carbon emissions runs out at the end of 2012.
The annual meeting in Tokyo also called for urgent action to cope with rising world food prices.
The joint statement was issued by European Commission chief Jose Manuel Barroso, Japanese Prime Minister Yasuo Fukuda and Prime Minister Janez Jansa of Slovenia, the current EU president.
Japan wants this year's G8 summit to shape the course of negotiations to reach a post-Kyoto Protocol deal by the end of 2009 on curbing global warming.
But the joint statement fell short of giving a specific figure for binding cuts.
The European Union has proposed emissions reductions of 20 to 30% by 2020 from 1990 levels.
Japan has joined the United States in saying it is too early to set numbers for future emission curbs.
Japan and the EU also called for action to address spiralling food and oil prices, which they said "could slow down the growth in the global economy and have negative effects on developed and developing nations."
Jose Manuel Barroso told a news conference after the summit that a fall off in official development aid for a second straight year in 2007 was "alarming".