The United States has joined with the EU and a range of other countries at COP21 in an effort to secure a final agreement. The so called "high ambition coalition" now comprises well over 100 countries from the rich and developing world. As well as the US, Norway, Mexico and Colombia have offered their support to the alliance.
Delegates worked through the night on a draft text of the agreement with a further version likely on Thursday. On Tuesday the European Union joined with 79 countries from Africa, the Caribbean and the Pacific to push for an "ambitious, durable and legally binding" deal with a strong review every five years.
On Wednesday, the US joined the grouping, which, although it will not be a formal negotiating block, has set out a common position on what the Paris agreement must achieve.
"We will be fighting for some very basic issues," said Tony De Brum, foreign minister of the Marshall Islands. "Strong recognition of the below 1.5-degree temperature goal, a clear pathway for a low-carbon future, five-yearly updates and a strong package of support for developing countries, including delivery of $100bn per annum," he said.
US lead negotiator, Todd Stern, echoed the call for the 1.5-degree target to be recognised in the eventual agreement. "We need beyond the below 2-degree target; we need to have a recognition of 1.5 degrees in the agreement and we need a very strong and balanced transparency article so everybody knows what we are all doing.
"This is our moment and we need to make it count," he said.