Copenhagen: Prospects of finalising a new binding agreement on climate change by the end of the year are "slim", according to UN climate convention chief Yvo de Boer.
He was speaking at the first UN climate talks since the Copenhagen summit.
A negotiating process was agreed, but big divisions remain between nations.
Analyses show pledges in Copenhagen are not likely to keep the global average temperature rise below 2C (3.6F).
"We see that with current pledges, we wouldn`t reach that objective - this is why we were here, and this is why we are working to increase ambition," the BBC quoted Spain`s delegation chief Alicia Montalvo Santamaria, as saying while speaking for the EU.
Grenada`s Ambassador Dessima Williams, who chairs the Association of Small Island States (Aosis), said that despite agreement on how negotiations should proceed through the year, there were still hurdles to cross in terms of what a new global deal might look like.
"The question now is whether or not there will be a sense of ethical commitment [from high-emitting countries]," she told BBC News.
On the final evening of the three-day meeting, delegates took more than four hours to agree apparently simple matters such as how many times to meet over the year, and how the chair should write a draft negotiating text.
The protracted wrangles are rooted to a large extent in the debris of Copenhagen, in particular in the mistrust engendered when on the final day, a small group of countries wrote and then agreed the Copenhagen Accord, a political declaration entailing voluntary carbon curbs from major emitting countries.
Here, developed nations such as the US and Australia lobbied for the accord to be incorporated into any new global agreement. But developing countries decried it as far too weak, and objected to the "undemocratic" nature of the process.