Two weeks of climate talks organized by the United Nations finished with developing countries demanding more clarity from their richer counterparts on when a promised package of $100 billion in aid will materialize.

Envoys from almost 200 nations are leaving Bonn, Germany, on Thursday without producing a draft negotiating text for ministers to discuss at the end of the year. Instead, they planned another round of negotiations in Bangkok before their annual conference in Poland in December.

The holdup threatens to unravel three years of work to complete the Paris Agreement, a landmark deal reached in 2015 that set out an ambition to limit fossil-fuel pollution in all nations for the first time. Negotiators are working toward writing a rule book that will help bring the pact into force even as U.S. President Donald Trump vowed to withdraw from the Paris framework.

Rich countries, led by the U.S. and European Union, pledged in 2009 to ramp up climate-related aid to $100 billion a year by 2020. While they have made progress on that commitment, reaching $62 billion in 2014 according to one official study, developing nations want more detail on what money is coming before signing on to the Paris rules.

Bloomberg News