Leaders of the Group of Eight nations wrapped up their annual summit Wednesday by reaching a consensus with other major greenhouse gas emitters on the need for ''deep cuts'' in global emissions, but failed to win agreement on a specific numerical target despite their call for the world to share the vision of halving emissions by 2050.

Hailing ''significant achievements'' made amid multiple pressing global issues, summit chair Japanese Prime Minister Yasuo Fukuda said, ''In overcoming differences in positions among the G-8 members and showing a common understanding (on the 2050 target), I believe we have contributed to building momentum for U.N. negotiations.''

Fukuda also warned at a closing news conference that the G-8 will impose sanctions on Zimbabwe over the political violence there if the U.N. Security Council reaches an agreement to do so, clarifying the ''financial and other measures'' clause in the leaders' special statement issued a day earlier.

Britain and the United States are pushing for the council to tighten sanctions on Zimbabwean President Robert Mugabe and his aides, including travel bans, an asset freeze and an arms embargo.

On soaring food and oil prices, which along with climate change and concerns about the global economy topped the agenda, the G-8 agreed with heads of five key emerging nations Wednesday to strengthen agricultural assistance especially to small-scale farmers and on the need to remove food export restrictions, a Japanese Foreign Ministry official said.

''This is the summit that for the first time has committed itself as the G-8 to a target for 2050 if an international agreement can be met,'' British Prime Minister Gordon Brown told a news conference. ''This is real progress on climate change and we've taken things a very big step forward.''

''At the same time today, I think developing countries are recognizing that they have also got to make major steps forward in their commitments to climate change reductions,'' he said.

In negotiations on combating climate change, the G-8 leaders agreed with the heads of Brazil, China, India, Mexico, South Africa, Indonesia, South Korea and Australia to commit to ''common but differentiated'' responsibilities, with developed nations to set medium-term goals and developing economies to curb rises in future emissions.

At the U.S.-initiated Major Economies Meeting on Energy Security and Climate Change on Wednesday morning, the leaders also stressed the importance of more innovative technologies as well as adaptation measures to address the adverse impacts of climate change.

''We support a shared vision for long-term cooperative action, including a long-term global goal for emission reductions, that assures growth, prosperity, and other aspects of sustainable development, including major efforts towards sustainable consumption and production, all aimed at achieving a low carbon society,'' they said in a declaration but without specifying the target.

In an apparent attempt to dismiss skepticism over the vagueness of a G-8 statement Tuesday which said the leaders agreed to seek to adopt the goal of at least halving emissions by 2050 with no base year set, Fukuda offered clarification by saying, ''Of course that is based on the premise that we as the G-8, including the United States, have agreed (on the target).''

Fukuda also said the latest G-8 agreement envisages that the base year for a long-term goal should be the present time instead of 1990 as stated in the Kyoto Protocol.

U.S. President George W. Bush said that ''significant progress'' has been made at the summit and related talks among major emitters toward a comprehensive approach to addressing global warming.

In a separate outreach dialogue over breakfast, the G-8 and Brazil, China, India, Mexico and South Africa -- known as the Group of Five as emerging nations -- agreed to cooperate on suppressing high food prices but remained apart on the Doha Round of World Trade Organization free trade negotiations, another Japanese Foreign Ministry official said.

''The sense of urgency displayed by the G-8 in tackling the most immediate food, nutrition and agricultural inputs needs of tens of millions of hungry people worldwide is encouraging,'' U.N. Secretary General Ban Ki Moon said in a statement on the summit's outcome.

''We must make more progress in reducing agricultural subsidies in industrialized countries...and in lifting export restrictions and tariffs in order to strengthen trade and markets in low-income developing countries,'' said Ban, who also took part in the summit in Hokkaido's Lake Toya resort.

The emerging nations stressed particularly the need to increase food production to alleviate the impact of soaring prices especially on the poor and pointed to the rise in oil prices, use of biofuels and speculative funds as factors.

Meanwhile, the G-8 called for the emerging nations to follow the same standards set by the Organization for Economic Cooperation and Development on providing development assistance, remarks that were apparently targeted at China's aid activities in Africa.

As the first gathering at the leader's level among major industrialized and developing nations since a U.N. climate change meeting involving 190 countries in Bali late last year, the MEM discussions on Wednesday were at the center of global attention.

While the response from China and India, two major emerging powers and emitters, to the G-8's call is seen as being key to determining the direction of negotiations from now on, only South Korea, Australia and Indonesia threw their support behind the G-8's call to share the 2050 goal.

The G-5 nations have requested that industrial countries slash emissions by 25-40 percent below 1990 levels by 2020. Meanwhile, the G-8 side stresses that the participation of all major economies, both developed and developing, in a post-2012 framework is essential.

The participants, however, agreed to continue the MEM process and the leaders will meet again at next year's G-8 summit to be held in La Maddalena, Italy.

Fukuda issued a chairman's summary that underscored the G-8's determination to tackle global warming and other global challenges and emphasized that cooperation from the emerging countries will be essential to realize the envisioned new framework after the current Kyoto Protocol expires.

It also reiterated the G-8's concerns about soaring commodity prices, and called for strengthening the nonproliferation regime, including having North Korea and Iran abandon their nuclear ambitions.

The G-8 involves Britain, Canada, France, Germany, Italy, Japan, Russia and the United States. The European Union is also represented at the summit.

(Takehiko Kajita also contributed to this article.)

==Kyodo