The first in-person meeting of climate ministers in 18 months has seen some tentative progress, says the UK minister who will lead the Glasgow COP26 meeting.
Alok Sharma said that the countries aligned more closely on climate issues but on some key matters they were "not yet close enough".
One of the outstanding questions is the phasing out of coal for energy.
Continued use was incompatible with a key climate target, Mr Sharma said.
Representatives from 51 countries attended the informal gathering in London over the weekend.
COP26 will aim to raise ambition on tackling climate change - in order to avoid far-reaching consequences for the planet.
With just three months until the Glasgow summit, there has been a flurry of scientific and diplomatic activity in recent days related to climate change.
Scientists from the Intergovernmental Panel on Climate Change (IPCC) - the UN's climate science body - have begun two weeks of discussions to try and agree a new report on the state of the global climate.
On the political front, environment ministers from the G20 group of nations met in Naples, Italy, last week to try and make progress on questions such as the elimination of coal from power generation.