U.S. President George Bush has recently urged countries to agree on long-term goals for greenhouse gas emissions.

Speaking ahead of next week's G8 summit, he said he would hold meetings bringing together the U.S. and 14 other major emitters to set targets by the end of 2008.

German Chancellor Angela Merkel welcomed the U.S. proposal, saying it was "common ground" for action. Germany is expected to call for cuts in emissions at the G8 summit.

BBC environment analyst Roger Harrabin says Mr Bush's speech was short on details, and White House aides have made clear Mr Bush will oppose demands for the U.S. to cut emissions and join a global carbon trading system.

Meanwhile, Micah Challenge UK, a coalition of Christian churches, organisations and leaders, is calling on Christians to pressure world leaders on their promises to the poor by joining the 'The World Can't Wait' rally in London this weekend.

The rally, to be held on Saturday on the banks of the River Thames, comes before the G8 leaders meet in Germany to discuss issues including the fulfilment of the Millennium Development Goals agreed in 2000.

The World Can't Wait Rally aims to call on world leaders ahead to deliver on their promises and take decisive action against poverty and climate catastrophe.

Micah Challenge UK is part of the international Micah Challenge movement of Christians lobbying their governments to do more to ensure the fulfilment of the MDGs to alleviate extreme poverty by 2015.