The COP15 climate change summit in Copenhagen has closed with an accord put forward by the US, which said the UN would work towards limiting the rise in global temperatures to below 2 degrees above pre-industrial levels.
It gave no commitment to reducing greenhouse gas emissions or timetable for achieving a legally binding agreement.
The accord was accepted by a small number of countries including China, India and Brazil but has not yet received unanimous support.
Achim Steiner, UN Under-Secretary General and Executive Director of the UN Environment Programme (UNEP) admitted the talks had not delivered the breakthrough many had hoped for.
'Trying to take over 190 countries through the same door towards a more cooperative global warming policy has proved challenging,' said Mr Steiner.
Mr Steiner said the aim of limiting a global temperature rise to below 2 degrees had fallen short of the calls of many countries, including ones in Africa and small-island developing states, which had been urging for global average temperatures to rise no higher than 1.5 degrees.
Scientists say developed countries need to make greenhouse gas emission cuts of at least 40 per cent by 2020 to give the world a chance of avoiding temperature rises of more than 2 degrees.
Greenpeace said that without an agreement to cut emissions the US-led accord was a failure. 'It is not fair, not ambitious and not legally binding. The job of world leaders is not done.'
Despite the lack of support so far from other countries, UN Secretary General Ban Ki-moon said the US-led Accord needed to be transformed into a legally binding treaty next year.
While the talks failed to deliver a deal on emissions, an agreement was reached for developed countries to try to raise $100 billion a year by 2020 to help less industrialiased countries adapt and mitigate against climate change.
However, there were fears that wealthier countries would try to force other countries into accepting the accord put forward by the US by threatening to withhold the $100 billion in mitigation and adaption funds agreed if they refused.