Five days before hosting a summit of the Group of 20 nations, US President Barack Obama said on Saturday that steps taken since they last met in April in London had produced "real progress" to overcome the global economic crisis.

The US President is preparing to meet with other G20 leaders in Pittsburgh.

Since the meeting in London,some progress has been made. But some think the efforts to stop the global economic meltdown are not enough.

Barack Obama, US President, said, "We know we still have a lot to do, in conjunction with nations around the world, to strengthen the rules governing financial markets and ensure that we never again find ourselves in the precarious situation we found ourselves in just one year ago."

The London summit in April was held at the height of the global financial crisis. This crisis has required unprecedented international cooperation to jump-start the world's economies.

Financial market reform will be a central issue at Pittsburg's summit.

Barack Obama, US President, said, "At next week's G20 summit, we'll discuss some of the steps that are required to safeguard our global financial system and close gaps in regulation around the world - gaps that permitted the kinds of reckless risk-taking and irresponsibility that led to the crisis."

In Asia, leaders also considered these issues.

South Korean President Lee Myung-bak said he wanted "well-sequenced exit strategies" implemented around the world in the coming months. But he added global leaders should not act hastily.

Lee Myung-bak suggested that G20 leaders agree on general principles on the implementation of exit strategies, leaving the timing to individual countries. He warned of a double-tip recession if policy measures were withdrawn prematurely.