U.S. President Barack Obama has called German Chancellor Angela Merkel to discuss the latest developments in the eurozone crisis .

The White House said that in the telephone talk Friday President Obama and Chancellor Merkel also discussed preparations for the G20 summit next month in France.

U.S. officials have accused European Union leaders of not acting swiftly enough to avert the crisis which they say could send the global economy into a new recession. Ms. Merkel rejected the criticism earlier Friday, saying those outside the eurozone have no right to urge the bloc into action.

She also defended her gradual approach to the debt crisis, saying that a solution to the problem that had built up over decades cannot be found overnight.

The finance ministers of the world's 20 biggest economies are meeting in Paris Saturday to try to resolve the European debt crisis that is threatening to push world economies into another recession.

They are expected to consider several options that some leaders say could help stabilize the global financial markets and ease the debts of financially troubled Greece.

European leaders are pressing the continent's banks to sharply increase their cash reserves to cover possible losses on the debt they hold from Greece and other countries. U.S. investment bank Goldman Sachs suggested the European banks may need to add more than $400 billion to their reserves.

Still others think the lending capacity of the International Monetary Fund should be increased. But U.S. Treasury Secretary Timothy Geithner rejected the idea, saying that Europe has enough of its own money to solve the debt crisis.