COPENHAGEN, Denmark - It was a mercurial Monday in the Danish capital as climate talks resumed after an earlier boycott by the developing world stalled negotiations for several hours.

The move drew a scolding from Environment Minister Jim Prentice for wasting what precious little time's left to reach a new greenhouse-gas deal.

Negotiators from China, India and other emerging economies walked out of the negotiations in Copenhagen over a dispute about how much rich countries should reduce their greenhouse-gas emissions.

The Harper government aims to lower Canada's emissions 20 per cent from 2006 levels by 2020. The U.S. recently put forward a similar goal.

The so-called Group of 77 countries wanted industrialized nations to take on steeper targets. The developing countries -- which are actually 135 in number -- were trying to shift the focus to rich nations' responsibilities in the fight against climate change.

Formal working groups were put on hold until negotiators broke the impasse later in the afternoon in a series of informal talks.

European Union environment spokesman Andreas Carlgren said both sides "found a reasonable solution."

But the move broke momentum as the talks are in their final days.

More than 100 world leaders are to arrive in Copenhagen later this week, and it was hoped some kind of deal would greet them at the airport.

But the boycott, led by African countries, appears to have set back negotiations at a time when talks are already unravelling over disputes about financing for developing countries.

Prentice told reporters Monday that the protest by the developing nations didn't help matters.

"We have lost some time, there is no doubt about that," he said.

"That is not particularly helpful. But, all in all, it's our responsibility to get on with it and continue to negotiate."

Part of the problem is the Kyoto Protocol. Some countries, including Canada, want all or part of Kyoto rolled into a new deal in Copenhagen.

The Harper government has long maintained that any deal that doesn't include the United States, China and other big polluters -- and Kyoto doesn't -- isn't worth signing.

Canada's former Liberal government signed on to Kyoto, but the Harper Conservatives reneged on it, saying years of inaction by the Liberals means enacting the treaty's deep cuts would wreck the economy.

So Prentice and his top climate envoy, Michael Martin, have pushed for countries to agree on a single deal in Copenhagen.

But some countries want those nations that ratified Kyoto to abide by its commitments.

Poorer countries and China say Copenhagen is shaping up to be Kyoto's death knell.

Whether a Copenhagen deal includes or doesn't include Kyoto is seen as a major hurdle to overcome during these talks.

Another issue is financing. The developing world is calling for rich countries to pour billions of dollars into a fund they could tap into to help deal with the effects of climate change.

Commonwealth countries agreed to a similar idea at their recent summit in Trinidad. But who pays, and how much, is emerging as another obstacle to a deal in the Danish capital.