Chinese Premier Wen Jiabao and U.S. President Barack Obama meet on the sidelines of the Copenhagen climate conference.Photo: White House/Pete SouzaCOPENHAGEN — U.S. President Barack Obama and Chinese Premier Wen Jiabao made “progress” in talks here on key issues threatening to derail the push for a new world climate change pact, a U.S. official said.

Obama and Wen met for 55 minutes on the sidelines of the final day of the U.N. climate conference in Denmark, the official said on condition of anonymity, describing the session as “constructive” and saying it “made progress.”

The two leaders discussed three of the most contentious areas blocking the path to a climate deal on the last day of the summit: verification guarantees, financing to help developing nations deal with climate change, and permitted emission levels.

The official told reporters that Wen and Obama asked their negotiators to get together after their meeting to search for an agreement.

China and the United States have emerged as the key players at the summit, broadly representing the concerns of the developing and developed world, as the clock runs down on the search for a robust climate-change agreement.

The White House released a picture of the meeting, in the Bella Center in Copenhagen, showing Obama leaning towards Wen, locked in intense conversation, as the two leaders sat before their respective national flags.

UPDATE: China and the United States have traded sharp barbs during U.N. climate talks, but the world’s two biggest carbon polluters have somewhat closed the gap on the key issue of verification, experts said Friday.

How to monitor national pledges on carbon pollution featured high on the agenda when Obama and Chinese Premier Wen Jiabao talked for nearly an hour Friday on the sidelines of the largest-ever climate summit, officials from both countries said.

The movement toward detente on the issue was also reflected in statements by both leaders.

Washington has long said that any voluntary efforts made by Beijing and other major emerging economies to slow carbon emissions must be independently measured, reported, and verified — “MRVed” in climate-change lingo.

Coming into the 12-day meeting, set to end Friday, China indignantly rejected such demands. It invoked national sovereignty, its status as a climate victim, and the historic responsibility of rich nations to clean up the carbon mess.

But both sides seems to have moved toward compromise on this potentially deal-breaking issue over the last 48 hours, analysts say.

China and the United States together account for more than 40 percent of the world’s emissions of greenhouse gases from fossil fuels. Yet both lie outside the binding constraints of the Kyoto Protocol. The United States has snubbed that treaty, while China, as a developing country, has no targeted commitments.

Locking both countries into a post-2012 global treaty is therefore vital. And the U.S. says there can be no deal unless China’s voluntary pledges are open to scrutiny.

In Copenhagen, U.S. Sen. John Kerry and Secretary of State Hillary Clinton have played “good cop, bad cop” roles, suggests Isabel Hilton, editor of London-based China Dialogue.

On Wednesday, Kerry, who is struggling to push climate legislation through the U.S. Senate, warned that countries that don’t join an international transparency regime cannot expect to dump high-carbon goods on the American market — “the kind of fighting talk the Chinese doesn’t like,” Hilton said.

“He is mainly talking to a domestic constituency, because one of the things Congress is going to say is, ‘How can you trust the Chinese?’” she added.

The next day, Clinton softened the tone, talking about “a commitment to pursue transparency” and the bottom-line requirement, Hilton and other experts agreed.

“Clinton’s emphasis on transparency rather than MRV signals a real shift,” said Tim Nuthall, an analyst at the European Climate Foundation in Brussels.

Clinton’s statement caused the Chinese to scramble, postponing a press conference, he said.

When Chinese deputy vice foreign minister He Yafei finally spoke several hours later, the tone was also more conciliatory. “We will promise to make our actions transparent,” he said, adding that they would fall “under the supervision and monitoring of the law and by the media.”

He added: “We will also consider, in terms of mitigation actions, international exchange, dialogue, and cooperation that does not intrude or infringe on China’s sovereignty. “We are not afraid of supervision, responsibility, or to be monitored.”

A senior U.S. official, speaking on condition of anonymity, said He’s comments indicated China “had begun to move on the issue, and we look forward to working with them to resolve that issue.”

Both Wen and Obama trod carefully in speeches Friday, but the narrowing of the verification gap was in evidence.

Wen said China would “further enhance” its monitoring regime, as well as “increase transparency and actively engage in international exchange, dialogue, and cooperation.”

Obama took a tougher line, saying any global climate deal “where we all are not sharing information and ensuring we are meeting our commitments … doesn’t make sense. It would be a hollow victory.”

But he also added, “These measures need not be intrusive, or infringe upon sovereignty.”

Hilton suggested: “The Chinese have been very hostile to MRV because they thought the Americans were going to insist on factory-by-factory bilateral verification, which would open China up to all kinds of potential trade disputes and interference in energy policy. But the Americans do not appear to be asking that, so the Chinese have no problem with that.”

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