Members of the G20, which represent about 85 percent of the world economy, will be meeting Thursday and Friday in Pittsburgh. US President Barack Obama is expected to press for reforms aimed at easing global economic imbalances, to prevent a repeat of the financial crisis.

The US President is calling on world leaders to craft plans to reshape the global economy in response to the deepest financial crisis since the Great Depression.

Barack Obama, US President, said, "And 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."

But some analysts think recent welcome news that the economy is recovering could hamper reform efforts.

Daniel Price, Sidley Austin Law Firm, said, "...there is a risk, as we begin to turn the corner, it leads to complacency about pursuing an aggressive regulatory reform agenda."

German Chancellor Angela Merkel, who is seeking re-election next weekend, says she's "thoroughly optimistic" that a deal could be done on reforming financial markets.

For years, economists had warned of the dangers of economic imbalances. The US consumer was driving the global economy.

Now with housing prices down and unemployment still rising, Washington wants other countries to become engines of growth.

The G20 leaders are due to discuss other issues in Pittsburgh. These include climate change, ahead of important UN negotiations on emissions levels in December.

But differences between rich and developing countries already prevented G20 finance ministers from agreeing measures to curb global warming.

For G20 host President Obama, the summit will be something of a test. While his global starpower remains strong, there are questions emerging about what he can deliver.

(CCTV September 22, 2009)