U.N. climate talks began anew Monday in Germany, three months before world governments are supposed to adopt a landmark deal to fight global warming.

The climate pact envisioned for Paris in December will be a crucial test for the diplomatic process, which failed to deliver a strong deal six years ago in Copenhagen.

U.N. officials note things look much brighter this time around because most major economies have already presented national plans to limit their emissions of climate-warming gases after 2020, when the new deal is meant to take effect.

Still, much work remains on how to ensure that countries live up to their pledges and how to divide the responsibilities of climate action among countries in different stages of development.