The UN Secretary General Ban Ki-moon has welcomed the US -backed climate deal in Copenhagen as an "essential beginning".

He was speaking after delegates passed a motion recognising the agreement, which the US reached with key nations including China and Brazil.

But Ban said the agreement must be made legally binding next year.

Earlier, the meeting failed to secure unanimous support, amid opposition from some developing nations.

Several Latin American countries, such as Nicaragua and Venezuela, were among a group saying the agreement had not been reached through proper process.

Delegates at the climate summit had been battling through Friday night to prevent the talks ending without reaching a final deal.

The Copenhagen Accord is based on a proposal tabled on Friday by a US-led group of five nations – including China, India, Brazil and South Africa – that President Barack Obama called a "meaningful agreement".

The accord includes a recognition to limit temperature rises to less than 2?C and promises to deliver $30bn (€34bn) of aid for developing nations over the next three years. It outlines a goal of providing $100bn a year by 2020 to help poor countries cope with the impacts of climate change.

The agreement also includes a method for verifying industrialised nations' reduction of emissions. The US had insisted that China dropped its resistance to this measure.

"The conference decides to take note of the Copenhagen Accord of 18 December, 2009," the chairman of the plenary session of the UN Framework Convention on Climate Change (UNFCCC) declared yesterday morning, swiftly banging down his gavel.

Ban told journalists: "It may not be everything we hoped for, but this decision... is an essential beginning."

But the secretary general also said: "We must transform this into a legally binding treaty next year.

"The importance will only be recognised when it's codified into international law."

The UK's climate change secretary Ed Miliband said it was very important that the adoption of the accord would allow the flow of money to begin.

But, he said: "We recognise there could have been more ambition in parts of this agreement. Therefore we have got to drive forward as hard as we can towards both a legally binding treaty and that ambition."

Earlier, the proposal had been rejected by a few developing nations which felt that it failed to deliver the actions needed to halt dangerous climate change.

The main opposition to the five-nation accord had come from a bloc of Latin American countries containing Nicaragua, Venezuela, Cuba, Ecuador and Bolivia.

Venezuelan delegate Claudia Salerno Caldera said before the motion was passed: "Mr President, I ask whether – under the eye of the UN secretary general – you are going to endorse this coup d'etat against the authority of the United Nations."

Lumumba Stanislaus Di-Aping, the Sudanese negotiator, had said the draft text asked "Africa to sign a suicide pact".

During the two-week gathering, small island nations and vulnerable coastal countries had been calling for a binding agreement that would limit emissions to a level that would prevent temperatures rising more than 1.5?C above pre-industrial levels.

Media throughout the world reacted to the deal. Britain's Guardian newspaper said the summit had failed to lay any foundations for a new carbon order.

"The progress on financial assistance over the fortnight is welcome, but with much of the money earmarked for climate adaptation, the global community is left resembling an alcoholic who has decided to save up for a liver transplant rather than give up drink," it said.

For the Los Angeles Times, President Obama had put pragmatism ahead of theory to protect America's self-interest.

But others were less than supportive. In the Huffington Post, blogger Johann Hari said life-saving ideas suggested by poor countries had been discarded by rich ones.

"They didn't seal the deal; they sealed the coffin for the world's low-lying islands, its glaciers, its North Pole, and millions of lives," he wrote.

In France, Liberation newspaper lamented the speed and commitment to saving the planet compared with saving the global financial system.

"We must make the bitter observation: when it comes to rescuing the banking system, the dialogue has been far more effective and determined.

"It is clearly easier to save finance than it is to save the planet," the paper wrote.

Italy's La Stampa newspaper called it "a façade of an accord" an "entente signed at the last minute at the end of a frantic day and aimed at saving face".

The DEAL on climate

• No reference to legally binding agreement

• Recognises the need to limit global temperatures rising no more than 2ºC above pre-industrial levels

• Developed countries to "set a goal of mobilising jointly $100bn a year by 2020 to address the needs of developing countries"

• On transparency: Emerging nations monitor own efforts and report to UN every two years. Some international checks

• No detailed framework on carbon markets ? "various approaches" will be pursued