LONDON, (Reuters) – The United States pledged $275  million to rainforest protection yesterday, at an event hosted  by Britain’s heir to the throne, Prince Charles, in London.

The money would come from $1.2 billion assistance for  international programmes, part of a 2010 budget currently  pending U.S. Congress approval.

Prince Charles has championed the protection of tropical  forests as a way to curb climate change and preserve wildlife,  and wants funds to fill a policy vacuum before a new U.N.  climate deal comes into force in 2013.

A climate summit in Copenhagen next month is expected to  approve a new scheme whereby rich nations pay the developing  world to protect tropical forests under a successor treaty to  the existing Kyoto Protocol after 2012.

Funding has been a major stumbling block in faltering U.N.  climate talks. At a ceremony in London U.S. Ambassador Louis  Susman read out a letter, from senior Democrat Senator Patrick  Leahy to Prince Charles pledging $275 million.

The funds would aim “to protect biodiversity and support  sustainable landscapes in fiscal year 2010 … with a focus on  protection of tropical forests”, a U.S. Embassy London spokesman  confirmed. A lot of the money would go to the Amazon and Congo  basins in South America and Africa, he added.

Destruction of tropical forests accounts for about 12  percent of global carbon emissions, scientists said this month,  and paying countries to maintain their forests is considered one  of the cheaper ways to fight global warming.

“Paying a relatively small amount to protect them is an  absolute bargain,” said Greenpeace Executive Director John  Sauven, welcoming the U.S. announcement.

The U.S. pledge follows an offer last week from Norway to  pay Guyana up to $250 million by 2015, and which has illustrated  the complexity of constructing such schemes.

Guyana’s forests have been far less logged than in many  tropical nations, covering three-quarters of the country, and  under the terms of the new deal with Norway, Guyana could  actually be paid while chopping trees at a faster rate.

When asked whether Guyana will be allowed to increase  deforestation under the agreement, Guyana’s President Bharrat  Jagdeo said: “Basically yes,” speaking to reporters, campaigners  and researchers in London late on Wednesday.

The memorandum states that Norway will compensate Guyana if  it does not cut down more than 0.45 percent of its forests per  year, but Guyana is felling trees at a far slower rate now.

“We are going to do some detailed work between now and  October 2010 when we will know what that figure is … That may  cause some adjustment,” said Jagdeo.