COPENHAGEN - US President Barack Obama returned at about 930 pm Friday evening (430 am Saturday, Manila time) to the Bella Center, the site of the collapsing climate change negotiations, to salvage what an anonymous official later called a "meaningful agreement."

A White House statement about an hour later announced that the United States had reached an understanding with Brazil, South Africa, India and China, the so-called BASIC group of the largest developing countries, on the crucial issue of verification of emission reduction targets, among other sticking points.

"Today, following a multilateral meeting between President Obama, [Chinese] Premier Wen, [Indian] Prime Minister Singh, and [South African] President Zuma a meaningful agreement was reached," the statement read. "It is not sufficient to combat the threat of climate change but it is an important first step."

The side deal is nowhere near even the modest expectations delegates had expected from the Copenhagen conference, but it packages a set of concessions from the five parties that promises to move the climate talks forward, after Copenhagen.

The five countries together account for half of all carbon dioxide emissions.

Obama did not stay long in his third visit in less than a day to the conference venue. He exited, through the back of a nearly empty press conference hall, after about 45 minutes.

He stopped to shake hands with the Danish ushers in the hall, but did not take questions from the journalists remaining in the room.