The row comes as UN Secretary-General Antonio Guterres warned countries that “failure is not an option”.

At the heart of the negotiations is a trade-off between promises of more money from developed countries and global commitments to reduce the use of fossil fuels.

Some developing and oil-rich countries are reluctant to take strong steps to cut fossil fuels because it could jeopardize their economic growth.

At a meeting open to all nations, EU climate action commissioner Wopke Hoekstra called the draft deal “unbalanced, unworkable and unsubtle.”

US climate envoy John Podesta said: “We are surprised that there is nothing that delivers… on what we agreed to last year in Dubai.”

“We will have failed in our duty and millions of people will already feel the effects of extreme weather conditions,” he added.

Samoan Minister Cedric Schuster, representing small island nations on the front lines of climate change, said:

“We cannot afford to undermine the progress made less than a year ago in Dubai.”

At the COP28 climate negotiations last year, nations agreed to “move away from fossil fuels”.

“If we don’t have ambition on mitigation, then everything else will fail,” said Eamon Ryan, Ireland’s environment minister, speaking to reporters.

Diplomats are unhappy that Azerbaijan, host of COP29. They say the draft agreement reflects the views of the Arab Group and the so-called Like-Minded Group, which includes Saudi Arabia, China, India and Bolivia.

The Saudis suggested that the fossil fuel deal reached was only an option for countries, rather than a specific instruction.

Minister Ryan said the proposed new agreement text reflected this view.

“We all know there was a pushback. There has been an attempt to interpret what we agreed last year as a menu, and to take back the language and the commitment, and this must stop also in the interest of the Arab group.