Poland on Thursday defended a contested "coal summit" that will be staged in Warsaw next week alongside climate talks on curbing Earth-warming fossil fuels.

The two-day conference is being organised by an industry group, the World Coal Association, with the "endorsement" of the economy ministry of Poland, the country hosting the UN talks.

Environment activists are planning to picket the ministry when the meeting starts on Monday.

Environment Minister Marcin Korolec, who chairs this year's UN negotiations, told journalists Thursday the coal meeting was only one of a panoply of events taking place on the sidelines of the climate forum.

"During those two weeks, we have a number of different meetings here," he said.

"This coal summit is organised in parallel, not in the framework of this conference. You have to take that into account".

The "summit" will bring together some of the world's largest coal producers and consumers, policymakers, academics and observers to discuss the role of coal in the global economy, in the context of climate change, according to the website.

Poland is a major user of coal, a cheap and indigenous but highly polluting energy source.

Polish Prime Minister Donald Tusk said in September that "hard coal and lignite -- and soon shale gas -- will remain our principal energy sources. That's where the future of the energy sector lies."

Korolec insisted on Thursday his country was a "leader" in the fight against climate-altering emissions.

According to statistics from the International Energy Agency (IEA), Poland was the world's ninth-biggest coal producer in 2012 with 144 million tonnes or 1.8 percent of the world total -- compared to China's 3.5 billion tonnes (number one at 45.3 percent) and the United States 935 million tonnes (second highest with 11.9 percent).

Poland was also the world's 10th biggest producer of electricity from coal and peat with 141 terawatts in 2011 - some 95 percent of its total electricity production. The country emitted 300 million tonnes of CO2 from fossil fuel combustion in 2011.

The UN has also entered the coal summit fray, with its climate chief under fire for agreeing to address the opening ceremony next Monday.

A number of non-government organisations urged Christiana Figueres in an open letter dated November 8 to withdraw from the engagement.

"Scientists are clear that we will need to keep at least two-thirds, and more likely over 80%, of known fossil fuels in the ground if we are to keep global warming rise below the agreed goal" of 2.0 degrees Celsius (3.6 deg Fahrenheit) over pre-Industrial Revolution levels, said the letter signed by Greenpeace, WWF and Oxfam, among others.

"It is outrageous that the World Coal Summit... will take place at the beginning of the second week of the climate negotiations... We would not like events promoting the most polluting of industries to become associated with solving climate change."

Figueres responded she would use the opportunity to "speak directly to an industry that must change quickly".