prefix = st1 /London 01 April 2009 U.S. President Barack Obama and British Prime Minister Gordon Brown are calling for global unity as world leaders gather in London for an emergency economic summit . The president says no one country can fix the economic crisis. Mr. Obama stressed the need for all participants to seek common ground to deal with the economic crisis.  "I am  ly confident that this meeting will reflect enormous consensus about the need to work together to deal with these problems," said Mr. Obama. There are signs of tension, as the G20 summit prepares to begin its work in London.  Some countries are blaming the United States for sparking the economic crisis through the deregulation of its financial scene - a move that sparked an economic recession . The president says the United Stateshas made mistakes, but so did other countries whose regulatory systems could not keep pace with a changing financial sector. He says it is time to look for solutions. "At this point, I am less interested in identifying blame, than in fixing the problem," he said. President says differences are overstated. France and Germanysay the emphasis should be on regulatory reform.  French President Nicholas Sarkozy even told an interviewer that he might walk out of the summit, if nations fail to agree on stricter regulation of global financial markets. Brown predicts no walkouts. President Obama says reports of differences are overstated.  And, Prime Minister Brown predicts no one will walk away from the summit and its important work." I am confident President Sarkozy will not be here for the first course of our dinner, but will still be sitting as we complete our dinner this evening," said Mr. Brown. Mr. Brown says "Never before has the world come together in this way to talk about an economic crisis," he said. "Any of the crises we have seen since the second World War, you have not had this level of international cooperation." Differences between leaders at the summit can be seen from the fact that  _  .
President Obama says differences are overstated. French President told an interviewer that he might walk out of the summit. Prime Minister Brown predicts no one will walk away from the summit. nations do not agree on stricter regulation of global financial markets.