African countries have said they are prepared to provoke a major UN crisis if the US and other rich countries do not start to urgently commit themselves to deeper and faster greenhouse gas emission cuts.

In a dramatic day in Barcelona, UN officials were forced to step in after 55 African countries, in an unprecedented show of unity, called for a suspension of all further negotiations on the Kyoto protocol until substantial progress was made by rich countries on emission cuts.

Earlier, the UN chair had been forced to abandon two working groups after the Africa group refused to take part.

The African countries were supported by all other developing country blocks at the talks. In a series of statements, the G77 plus China group of 130 nations, the Alliance of Small Island States (Aosis), the Least Developed Countries (LDC) group, as well as Bolivia and several Latin America countries, all broadly backed the African action.

The move by developing countries reflects their deep and growing frustration over the slow progress that industrialised countries are making towards agreeing cuts. With less than three days full negotiating time left between now and the opening of the final talks at Copenhagen, the split between rich and poor countries threatens to blow the talks fatally off course.

Bruno Sekoli, chair of the LDC group, said: "Africa and Africans are dying now while those who are historically responsible are not taking actions."

Algeria, which chairs the Africa group, backed by representatives from Gambia and Kenya, said rich countries were "more concerned with political and economic feasibility" while the poorest were "struggling to survive" with climate change.

In a press conference, the poorest countries demanded that the rich adopt the science-backed target of a 40% overall cut on emissions on 1990 levels. So far, rich countries have pledged an aggregate of less than 10%. The US, the world's second biggest polluter, has pledged to cut around 4% on 1990 levels, or 17% on 2005 levels.

In some of the most frantic diplomacy seen in the talks so far, delegates to hurriedly agreed to dedicate six of the 10 remaining negotiating sessions to discussions on mid-term emissions reductions. The decision received widespread support from all developing countries who stressed the importance of delivering real progress.

"African countries have shown they are not going to sit back and accept a bad deal in Copenhagen," said a spokeswomen for Oxfam international.

"The poorest countries say they are dying now and the rich are just sitting back doing nothing. Hopefully they will take action now," said Asad Rehman, head of international climate with Friends of the Earth.

"The world's largest historical emitter, the US, is missing in action during the climate negotiations, on its targets, on its finance – and the developing world is rightfully calling them out on it," said Greenpeace USA climate campaign director Damon Moglen.

"It is clear that for many countries, enough is enough. The fact that this has come today from countries including Kenya, President Obama's ancestral home, should be his wake-up call. Obama can no longer hide behind failed congressional legislation. He must provide ambitious, science-based emissions reductions targets and come to table in Copenhagen."

The talks, which are some of the most complex ever conducted, depend on all countries eventually agreeing to everything. They would be seriously jeopardised to the point of certain failure in Copenhagen next month if the African countries walk out again.