“He was in a hurry home, he said, because they were closing the airport in Washington,” Mr. Reinfeldt said of Mr. Obama. “There was a snowstorm coming in.”

Ed Miliband, the British secretary of state for climate and energy, acknowledged Europeans’ disappointment in the talks’ result but said he was “absolutely not in the blame game.” Rather, he said, negotiating strategies needed to be examined.

Delaying discussion of the toughest issues until the final moments of the conference came close to dooming the chances of an accord, Mr. Miliband said. “My biggest frustration at this conference is not talking about substance, apart from the last day, frankly,” he said.

Mr. Miliband said the months of jockeying leading up to Copenhagen had resulted in some benefits.

“The process has been a nightmare, but the substance of the last year means you have ambitious targets from lots of countries,” he said.

He noted that Brazil, South Africa, India, China and Japan were among the nations that had proposed limits on their emissions before the talks.

“The success of this process has been the fact that it has concentrated minds and has made all the major players put numbers on the table,” Mr. Miliband said.

But he added: “I would have preferred a much more comprehensive agreement. I think going forward there are some difficult issues if emerging economies don’t want to be part of a legal treaty — which they obviously don’t — about what is the framework in which you operate. We do want a legal treaty, and we will be campaigning for it, but I think there are some difficult issues there.”