The dickering at the Copenhagen climate conference prompted some chiding on Tuesday from UN Secretary General Ban Ki-moon.
Speaking on his arrival at UN climate change talks Copenhagen, he said rich and poor countries must "stop pointing fingers" and raise their climate targets.
Ban wants negotiators to settle their differences in the next few days, saying it would be a "serious mistake" to leave the main negotiations to world leaders. They arrive later this week.
"This is a time where they should exercise the leadership," Ban said. "And this is a time to stop pointing fingers, and this is a time to start looking in the mirror and offering what they can do more, both the developed and the developing countries."
On Monday, the G77 — a group of developing countries that includes China, Brazil and India — led a boycott of talks at the climate change summit.
Formal working groups were cancelled at the 192-country conference after developing states called for the 1997 Kyoto Protocol to be extended past 2012, when it is expected to expire.
The boycott ended later the same day following informal talks.
Ban warned that if negotiators cannot find a resolution before world leaders arrive starting Tuesday, "the outcome will be either a weak one, or there will be no agreement."
"This will be a serious mistake on the part of the negotiators and the leaders if they go back empty-handed," the secretary general said.
With files from The Associated Press