US President Barack Obama sought to swing the G20 spotlight back onto global imbalances and take his own country's policies out of the glare as world leaders gathered in Seoul on Wednesday.

An early G20 draft statement cited by Dow Jones Newswires echoed an earlier finance ministers' pledge to move toward more market-determined currency rates and appeared to offer no new proposals on how to ease tensions between struggling rich nations and new economic powers such as China or Brazil.

Obama, facing widespread criticism of US easy-money policy as he arrived for the two-day Group of 20 leaders summit, said a strong US economy was vital to the global recovery and urged his G20 counterparts to put aside their differences and do their part to bolster growth.

"When all nations do their part — emerging no less than advanced, surplus no less than deficit — we all benefit from higher growth," Obama said in a letter sent to G20 leaders on Tuesday. A copy was obtained by Reuters on Wednesday.

The bridge building came after a day of heated arguments as negotiators struggled to hammer out a closing statement that all G20 leaders could sign. Deep divisions have emerged over economic policy, particularly the US Federal Reserve's decision last week to spend another $600 billion buying government bonds.

Critics charge the Fed's policy weakens the dollar to the detriment of other nations, but Obama said the dollar's strength ultimately rests on the strength of the US economy.