U.S. President Barack Obama is calling on the world's leading industrial economies to move ahead with efforts to end the global recession.

In a statement released in advance of an upcoming Group of 20 summit, the president said "our work is far from complete" and urged leaders to focus on ways to sustain economic growth.

Mr. Obama also said efforts to increase growth have helped stabilize financial markets and expand trade but that G20 leaders must also find ways to avoid the types of "imbalances" that led to the global financial crisis.

G20 leaders are preparing to meet later September 24 and 25 in the eastern U.S. city of Pittsburgh.

Mr. Obama calls Pittsburgh "a bold example" of how to create new industries and jobs.

Finance ministers from G20 countries met in London on Saturday and promised they would not let a fragile global economic recovery collapse.

They also agreed on the need to continue spending trillions of dollars to stimulate economic growth - and the need to reform world economic institutions like the International Monetary Fund and the World Bank to better represent developing economies. 

Despite numerous indications that the world is pulling out of its deepest recession since World War II, U.S. Treasury Secretary Timothy Geithner says the world must still confront "significant challenges."

Differences also remain over how to reform a banking system that rewarded top bank executives with large salary bonuses, even though many of their decisions helped spark the financial crisis.