DURBAN, South Africa — Yvo de Boer said he left his job as the UN's top climate official in frustration 18 months ago, believing the process of negotiating a meaningful climate agreement was failing. His opinion hasn't changed.

"I still have the same view of the process that led me to leave the process," he told The Associated Press Sunday. "I'm still deeply concerned about where it's going, or rather where it's not going, about the lack of progress."

For three years until 2010, the Dutch civil servant was the leading voice on global warming on the world stage. He appeared constantly in public to advocate green policies, travelled endlessly for private meetings with top leaders and laboured with negotiators seeking ways to finesse snags in drafting agreements.

In the end he felt he "wasn't really able to contribute as I should be to the process," he said.

Today he can take a long view on his years as a Dutch negotiator in the 1990s and later as a senior UN official with access to the highest levels of government, business and civil society. He is able to voice criticisms he was reluctant to air when he was actively shepherding climate diplomacy.

Negotiators live "in a separate universe," and the ongoing talks are "like a log that's drifted away," he said. Then, drawing another metaphor from his rich reservoir, he called the annual 194-nation conferences "a bit of a mouse wheel."

De Boer spoke to the AP on the sidelines of the latest round of talks in this South African port city, which he is attending as a consultant for the international accounting firm KPMG.

Elsewhere in Durban Sunday, the South African host of the talks called for divine help at a climate change church service organized by the South African Council of Churches.

"We needed to pray for (an) acceptable, balanced outcome, that has a sense of urgency," said Maite Nkoana-Mashabane, who as South Africa's foreign minister is president of the Durban round of negotiations. Priests laid their hands on her head in blessing during the service.

De Boer said world leaders have failed to become deeply engaged in efforts to reach an international accord to control greenhouse gas emissions causing global warming. In recent years, their inattention has been compounded by their preoccupation with the economic and Eurozone crises.

Negotiators have been at the job so long -- since the 1992 climate convention -- that they have lost touch with the real world, he said. But it wasn't their fault.

"I completely understand that it is very difficult for a negotiator to move if you haven't been given a political sense of direction and the political space to move," he said, chatting on a hilltop terrace overlooking the Indian Ocean.

Rather than act in their own national interests, many leaders look to see what others are willing -- or unwilling -- to concede.

"You've got a bunch of international leaders sitting 85 stories up on the edge of a building saying to each other, you jump first and I'll follow. And there is understandably a reluctance to be the first one to jump," he said.

The 2009 Copenhagen summit was a breaking point. Expectations soared that the conference would produce an accord setting firm rules for bringing down global carbon emissions. When delegates fell short, hopes remained high that President Barack Obama, Chinese Premier Wen Jiabao, most of Europe's heads of government and more than 100 other top leaders would save the day at the last minute.

De Boer said he spent the last 24 hours of the summit in "a very small and very smelly room" with about 20 prime ministers and presidents, but the time was not ripe for the hoped-for international treaty.

Obama still hoped to push domestic legislation through the Senate, and any prior commitment to a UN treaty would have killed his chances. The bill died anyway. China and India, too, were not ready in Copenhagen to accept internationally binding limits on their emissions.

Many Americans, he said, have still not bought into the "green story," he said. In the meantime, the U.S. is losing a competitive edge against China, which is investing heavily to shift the course of its economy -- from which it will benefit regardless of the global warming issue, he said.

Despite their failures, De Boer said he thought most leaders sincerely want a deal on climate change.

"I do not see the negotiating process being able to rise to that challenge, being capable of delivering on that," he said. "I believe the sincerity on the part of world leaders is there, but it's almost as though they do not have control of the process that's suppose to take them there."