British Prime Minister Gordon Brown speaks during meeting with US President Barack Obama March 03, 2009 in the Oval Office of the White House in Washington, DC. The United States and Britain have launched massive economic stimulus packages since the collapse of US subprime home loans sparked a credit crunch that developed into the worst economic slowdown since the Great Depression. Brown has said he wants to use the Washington talks to prepare for a meeting of the Group of 20 developing and developed countries in London on April 2, which will aim to draw up a new blueprint for economic recovery. He will also deliver a speech to the US Congress on Wednesday, becoming the fifth British prime minister to do so.