Copenhagen, Dec 16 : The European Union may raise its greenhouse-emissions-cut target to 26 percent in a bid to overcome deadlock at a UN Climate Change Conference in Copenhagen, EU sources said Wednesday.

The 27-member bloc has already promised to reduce its emissions by 20 percent below 1990 levels by 2020.

Prior to the start of the Copenhagen conference, it said it would raise its target to 30 percent, but only if other major polluters came up with comparable offers.

The US has so far offered a 17 percent cut against 2005 levels. However, an earlier base year implies deeper cuts. But US negotiators say their longer term targets are far more ambitious.

The improved EU offer would involve an unconditional cut of 25 or 26 percent by 2020, or 30 percent by 2025.

Britain and France had been among the EU countries pushing for an unconditional 30 percent offer in Copenhagen.

Speaking to the BBC earlier Wednesday, British Prime Minister Gordon Brown said the Copenhagen talks faced "huge" but "not insurmountable" challenges.

The British premier also urged all sides to help seal a deal by Friday.

"We can't do it on our own, it's about the whole world coming together," Brown said.(DPA)