More countries are expected this week to pledge specific actions to limit carbon emissions over the next decade, in what would be very good news for arduous negotiations on a climate-change agreement, host country Mexico said.

Newly arrived government ministers begin applying political weight today to talks being held in Cancun, as the 193-nation UN climate conference moves into its decisive final week.

The meeting hopes to restore credibility to the talks after the last summit in Copenhagen a year ago, which failed to agree on any binding measures to rein in emissions of global-warming gases.

A nonbinding political document, the Copenhagen Accord, outlined important compromises among key players, including the United States and China, but its adoption was blocked by a handful of dissident nations.

In subsequent months, however, 140 countries declared their endorsement of the accord, and 85 of them made specific pledges for reducing carbon emissions, or at least limiting their growth, by 2020.

Mexico’s Deputy Foreign Minister Juan Manuel Gomez Robledo said more countries had said in private consultations that they intended to add their pledges to the list of 85.

Some countries that already have submitted pledges may take “additional measures”, he said. He declined to name any country, but said they included both industrial and developing nations.

“There has been a clear message from some parties, and that would certainly be very good news,” he told reporters today.

The Cancun talks seek to produce decisions on establishing a “green fund” to help poorer nations rein in greenhouse gases and to adapt their economies and infrastructure to a changing climate; an agreement making it easier for developing nations to obtain patented green technology from advanced nations; and pinning down more elements of a system for compensating developing countries for protecting their forests.

What will not be resolved at Cancun is the core dispute in the climate talks: fixing legally binding targets for nations to reduce greenhouse gases emitted by industry, vehicles and agriculture.

The pledges in the Copenhagen Accord are purely voluntary, and are insufficient to meet the goal scientists have set to limit the average global temperature to 2 degrees Celsius above what it was before the industrial age began.

Gomez Robledo said the side issues of funding, technology and forestry “are almost ripe”, and negotiators will work on disputed details over the next five days.