US President Barrack Obama on Thursday held telephone talks with British Prime Minister Gordon Brown over the forthcoming G20 Summit, the White House said in a statement.

Obama and Brown talked about preparations for a Group of 20 economic summit in Pittsburgh on September 24-25, White House spokesman Robert Gibbs said.

"They discussed ways to reform international institutions to provide key international players a greater role," the spokesman said.

Apart from the upcoming G20 summit, the two leaders also discussed preparations for the December meeting on climate change in Copenhagen, and "ways to make steady progress to ensure that both developed and developing countries fulfill their responsibility to combat climate change," Gibbs said.

Obama and Brown also exchanged views over the situation in Afghanistan, including the fighting against al-Qaida and their extremist allies in Afghanistan. Obama expressed his deep appreciation for Britain's sacrifices in Afghanistan war.

Britain deployed about 9,200 troops in Afghanistan. Some 210 British soldiers have died in the country since 2001.

(Xinhua News Agency September 11, 2009)