* Poor want clearer plans for aid towards 2020
* Warsaw talks in overtime due to deadlock (Adds new headline, recasts, updates throughout)
By Nina Chestney and Michael Szabo
WARSAW, Nov 23 (Reuters) - Talks to lay the foundations for a new U.N. climate pact due in 2015 were deadlocked as they ran into overtime on Saturday, with nations at odds over stepping up finance for developing countries to ease the impact of global warming.
The Warsaw meeting, which had been due to end on Friday, was meant to lay the groundwork for creating the first climate accord to be applicable to all nations by 2015, which would come into force after 2020.
However the only concrete measure to have emerged was an agreement on new rules to protect tropical forests, which soak up carbon dioxide as they grow.
Nearly 200 countries assembled at the U.N. conference have stumbled over three major issues over the past two weeks: the level of emissions cuts, climate finance and a "mechanism" to help poor countries deal with loss and damage from global warming.
"Climate change talks are still on knife edge after a long night. A few countries (are) insisting on looking backwards. Could be a long day," British Energy and Climate Change Minister Edward Davey said on Twitter.
Developed nations, which promised in 2009 to raise climate aid to $100 billion a year after 2020 from $10 billion a year in the period 2010-12, were resisting calls by the developing world to set targets for 2013-19.
A draft text merely urged developed nations, which have been more focused on spurring economic growth than on fixing climate change, to set "increasing levels" of aid.
It also suggested they report every two years on their approaches to stepping up finance levels to $100 billion.
A group of developing countries and China were in favour of an amendment to the text that "at least $70 billion" a year of climate finance is committed from 2016.
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The talks have also proposed a new "Warsaw Mechanism" which would provide expertise, and possibly aid, to help developing nations cope with loss and damage from extreme events such as heat waves, droughts and floods, and creeping threats such as rising sea levels and desertification.
Developing nations have insisted on a "mechanism" - to show it was separate from existing structures - even though rich countries say that it will not get new funds beyond the planned $100 billion a year from 2020.
Many delegates also said they wanted a clearer understanding of when nations will publish their plans for long-term cuts in greenhouse gases in the run-up to a summit in Paris in 2015.