AMSTERDAM - Wealthy countries are not going far enough to control greenhouse gas emissions, activists said Monday as delegates from 180 nations resumed talks on a global climate change pact.

Beginning a five-day meeting in Bonn, Germany, negotiators began trying to whittle down a 200-page draft into a workable treaty that will bring the world's carbon emissions under control over the next decade.

The talks have been deadlocked for months over demands by poor countries that a block of wealthy nations commit to deep cuts in emissions of heat-trapping gases by 2020, while rich countries demand that every nation share the burden.

The UN negotiations aim to forge a successor to the 1997 Kyoto Protocol, which set mandatory caps on emissions by 2012 in 37 rich countries but made no demands on other nations.

The next set of targets for 2020 is scheduled to be adopted at a major conference in Copenhagen, Denmark, in December. The pact is likely to include funding for poor countries to adapt to climate change and help them slow their own emissions while their economies grow.

On Monday, New Zealand became the latest country to announce a 2020 target, pledging to cut greenhouse gases by 10 to 20 per cent from 1990 levels.

The WWF environmental group criticized the goal as too weak, and slammed the government for caving in to industrial lobbies that presented "apocalyptic visions of a crippled New Zealand economy" if it tried to cut emissions from fossil fuels any further.

"Industrialized countries are failing on targets and need to go back to the drawing board," said Kim Carstensen, head of the WWF Global Climate Initiative.

In Wellington, New Zealand's minister for climate change, Nick Smith, said the announced target would be tough to reach because gross emissions were already 24 per cent above 1990 levels.

"This target means we're going to have to both catch up that 24 per cent increase as well as reduce emissions by 10 or potentially 20 per cent," he said.

The Bonn meeting is the latest in six rounds of talks scheduled this year, in addition to several summit meetings among major emitters. UN organizers described it as informal, meaning that more time will be spent in small negotiating groups and private sessions than in large plenary meetings.

Last week, South Korea said it will set an emissions target for 2020, the first country outside the 37 nations included in the Kyoto pact to set a national cap. The Seoul government said it would announce the target later this year, and it could range from 4 per cent below 2005 levels to 8 per cent above.

Although the target appeared modest, it was important since South Korea's economy had doubled between 1990 and 2005 and was continuing to grow, said Jake Schmidt of the Washington-based National Resources Defence Council.

Whichever number the Koreans chose, "the target would represent a serious cut from where they would be if the government took no action," Schmidt said on his blog. "Given the past and projected trajectory of emissions, this is a significant reversal."

Scientists say the world's most advanced countries should cut emissions by 25 to 40 per cent from 1990 levels if there is any hope of keeping the earth from warming by more than 2 degrees Centigrade (3.6 Fahrenheit).

Only the European Union has submitted a pledge approaching the limits recommended by UN scientists in a landmark report two years ago.

The United States, which rejected the Kyoto Protocol because it exempted countries like India and China from any obligations, has pledged to take the lead in negotiating a new accord. A bill that passed the House of Representatives would reduce emissions by 17 per cent from 2005 levels -- about 4 per cent below 1990 -- and the Senate is considering its own bill.