BARCELONA, Spain - African countries boycotted meetings at UN climate talks Tuesday, saying that industrial countries had set carbon-cutting targets too low for reducing global greenhouse gas emissions.

The action forced several technical meetings to be canceled at this week's UN climate talks in Barcelona. Delegates warned that, unless the African protest was settled, it could set back the timetable for concluding a new climate change pact at a major UN conference next month in Copenhagen.

The 50 or so African countries said they would only discuss pledges submitted by wealthy countries, and that talks on other issues including carbon offsets and action by developing countries should not move forward until there is full commitment by industrial countries.

"I don't think we can get to a result in the way we're going now," said Algerian negotiator Kamel Djemouai, who chairs the Africa group. "We cannot prejudge what will happen next until we see the reactions of others."

It was the first time the Africans have taken such concerted action at the UN climate talks, but they have been coordinating their position over the past year to ensure unity in the final lead-up to the Copenhagen conference, said Antonio Hill, of Oxfam International.

Scientists say industrial countries should reduce emissions by 25 to 40 per cent from 1990 levels by 2020, but targets announced so far amount to far less than the minimum.

The African walkout stymied only part of the talks, which operate in two parallel bodies. Negotiations on the overall shape of a deal and on financing for poor countries continued uninterrupted.

European delegates met leaders of the African group for two hours, but failed to persuade them to return to the committee rooms. A broader meeting was called to try to break the impasse.

Anders Turresson, the chief delegate from Sweden which holds the EU presidency, said that while EU leaders shared the Africans' concern about the low level of pledges, their tactic of limiting the discussion to emission targets was unproductive.

"I wouldn't call this situation a full deadlock," he said.

The larger group of more than 130 developing countries backed the African group's action, meant "to focus the mind" of the developed countries on the most important issue, said Sudanese Ambassador Lumumba De-Aping. He also indicated that walking out was a tactic often used in the negotiating process, and did not necessarily spell doom for the talks.

Climate Network Africa, a Kenya-based nongovernmental group, accused industrialized countries of not negotiating in good faith while Africans suffer from drought and floods.

Africa is seeking higher commitments "because we are under pressure, but the response (from developed countries) is that it is politically and economically difficult for them to put numbers on the table," said the group's director, Grace Akumu. "For us it is a question of life and death."

A landmark 2007 UN report based on the work of about 2,000 scientists predicted Africa would suffer the most from drought, agricultural damage, rising sea levels threatening coastal areas and the spread of tropical pests and diseases.

A new study published Tuesday says the glaciers on Africa's highest mountain, Kilimanjaro, have lost 85 percent of the ice they had in 1912, with more than a quarter present in 2000 gone by 2007.

The study, in the Proceedings of the National Academy of Sciences, cited Earth's rising temperatures as at least a partial cause. It said similar changes have occurred at Mount Kenya and the Rwenzori Mountains in Africa, as well as at glaciers in South America and the Himalayas.

The closed-door meetings stalled by the African boycott focus on technical issues related to emissions reductions, including identifying new greenhouse gases to be regulated and setting rules by which rich countries might offset emissions with green technology investments in poor countries.

Aid groups worried about the disruption. "It would be tragic if ... we were prevented from building the foundation of rules and accounting systems that will ensure the effectiveness of emission targets," said Duncan Marsh, of The Nature Conservancy.

In London, UN Secretary-General Ban Ki-moon admitted the climate change treaty may not be resolved this year, as nations may be unable to commit to firm emissions limits at Copenhagen.

"We may not be able to agree all the words," Ban said, adding that the Copenhagen pact could more likely be an agreement on principles -- rather than specific targets for cuts. "We need at this time the political will -- if there is a political will, there is a way we can come to a binding agreement in Copenhagen."

The Copenhagen deal would succeed the 1997 Kyoto Protocol, which called on 37 industrial countries to reduce heat-raising gas emissions by an average five per cent below 1990 levels by 2012. It made no demands on developing countries like India and China. The United States was the only major greenhouse gas emitter to reject the Kyoto accord.

On Monday, the U.S. came under renewed pressure to declare its intentions at the UN talks before the Dec. 7-18 Copenhagen meeting.

The U.S. says it is waiting for Congress to finish work on climate and energy legislation. Those bills, unlikely to be completed before the Copenhagen summit, suggest the U.S. would cut emissions only about 4 percent below 1990 levels over the next decade.

This week Republican Party senators threatened to boycott some of the congressional meetings, demanding additional studies on the bill's cost and job impact.

Hugh Cole, climate adviser for charity group Oxfam in Southern Africa, said resolving the Africans' protest was up to the U.S. and European Union.

"The world's poorest nations are faced with an impossible choice -- no climate deal or a bad climate deal," Cole said in a statement. He called on EU and U.S. leaders meeting Tuesday afternoon in Washington "to signal that they are willing to play their part."

German Chancellor Angela Merkel was also in Washington on Tuesday, urging both chambers of a skeptical Congress to "overcome the walls of the 21st Century" and emphasizing the need for a global agreement on climate change.

"We have no time to lose," she said. She said that while she recognized no deal could be successful without support from China and India, those fast-growing economies could be persuaded to sign on to a deal once it is struck.