Boris Johnson insists it is time for nations to put their differences aside and “come together for our planet and our people”.
The Prime Minister made the remarks ahead of travelling back to Glasgow for the final stretch of COP26.
Johnson, who is expected to take the train from London for the summit, will call on ministers and negotiators to bridge any remaining gaps in order to reach a consensus.
Negotiators from 197 parties are currently locked in talks to reach agreement on a range of key issues.
Those include establishing a common time frame for national commitments on emissions reductions and agreed methodology for countries to report on their climate action.
They are also working to agree progress on finance for nations most vulnerable to climate change and to address the issue of loss and damage in developing countries.
Johnson spoke at the opening ceremony of COP26 last week and welcomed world leaders to the summit.
But, the Prime Minister faced criticism after reports emerged that he flew back to London on a private jet in order to attend a private dinner.
Ahead of his return to Glasgow on Wednesday, Johnson said: “Negotiating teams are doing the hard yards in these final days of COP26 to turn promises into action on climate change.
“There’s still much to do. Today I’ll be meeting with ministers and negotiators to hear about where progress has been made and where the gaps must be bridged.
“This is bigger than any one country and it is time for nations to put aside differences and come together for our planet and our people.
“We need to pull out all the stops if we’re going to keep 1.5C within our grasp.”