Leaders of four major economies -- the United States, France, Germany and Britain -- held a video teleconference discussing climate change on Tuesday afternoon, the French president's office announced in a statement.

French President Nicolas Sarkozy, U.S. president Barack Obama, German Chancellor Angela Merkel and British Prime Minister Gordon Brown devoted the whole 50-minute talk to the negotiation about "essential points" concerning the ongoing Copenhagen Conference, Elysee Palace said.

The four parties decided to remain close contacts with other heads of state or government attending the climate conference in Copenhagen, the brief statement concluded.

As to the cut target of greenhouse gas emission, the European Union has committed to a reduction of 20 percent from 1990 levels and said it would raise the goal to 30 percent if others, first and foremost the United States, aim higher.

The United States insisted Tuesday its pledge of reducing carbon emissions by 17 percent from 2005 levels by 2020, equivalent to a reduction of 4 percent compared with 1990 levels.

Britain announced on Dec. 11 that it will provide 1.5 billion pounds (about 2.4 billion U.S. dollars) toward a three-year fund to help the poorest countries adapt to the effects of climate change.

As the Copenhagen negotiation went into the second week, negotiators are still wide apart on some key issues, such as emission cuts by developed nations and financial support for developing nations.