Negotiators released a new, shorter draft of an international accord to fight global warming Wednesday — and it leaves key issues unresolved just two days before high-stakes talks in Paris are scheduled to end.

U.S. Secretary of State John Kerry challenged diplomats to reach agreement by Friday's self-imposed deadline, promising American funding for countries hardest hit by the rising seas and extreme weather that scientists attribute to man-made emissions that are changing the world's climate.

The new draft document released by the U.N. climate agency is 29 pages, down from a 48-page version released Saturday. There are about 100 places where there are decisions still to be made, including multiple options left in brackets, or blank spaces.

One major issue remains money. The draft doesn't settle the question of the eventual responsibility of rich countries — historically the biggest emitters — to poor countries for future damage caused by climate change. The language on this so-called loss-and-damage question is identical to that in Saturday's version.

It doesn't resolve the question of the long-term goal of the accord — whether it is to remove carbon emissions from the economy altogether, or just reduce them. Nor does it settle whether governments are aiming at reducing overall global temperatures by 1.5 degrees above pre-industrial times or closer to 2 degrees.

The new text "definitely shows progress both in terms of the conciseness of the text as well as in terms of the crystallization of the political points that still need a lot of work," U.N. climate agency chief Christiana Figueres told reporters.

Those points include how to pay for adapting to climate change, how ambitious the accord should be, and how to define the obligations of countries in different stages of development in fighting climate change. She called them "the three biggest political issues that we have always known, but they now are very well crystallized for ministers to come together."

French Foreign Minister Laurent Fabius said, "Some progress has been made, but there is still a lot of work to be done."

He said negotiators had "a long night" before Wednesday's draft was submitted.

"We must prepare to be working all night and tomorrow — probably continuously," Fabius said.

Kerry, speaking at the conference outside Paris, announced Wednesday that the U.S. will double its contribution to helping vulnerable nations adapt to climate change impacts, increasing money for climate adaption grants to $860 million from $430 million by 2020. Developing nations have been demanding more money for adaption as they struggle with increased extreme weather events, like hurricanes, heavy rains and floods.

The money will be part of an existing promise by wealthy countries to jointly mobilize $100 billion a year by 2020 in climate finance. It will help fund domestic weather services and tracking systems to better assist poorer nations in forecasting and coping with extreme weather.

Kerry has made combatting climate change a priority project since he became secretary of state, and sounded familiar themes.

"Make no mistake: If, as a global community, we refuse to rise to this challenge — if we continue to allow calculated obstruction to derail the urgency of this moment — we will be liable for a collective moral failure of historic consequence," he said. "We are not just responsible to ourselves — we are responsible to the future."

Several activist groups staged small protests around Paris and the conference venue Wednesday pushing for an ambitious climate accord, from Greenpeace with a huge mechanical polar bear to others dressed up as Star Wars characters Yoda and Storm Troopers.

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Angela Charlton, Karl Ritter and Matthew Lee contributed to this report.