South Korea's trust in US Treasury debt securities had not changed despite the US loss of its AAA credit rating, Choi added.

He declined to elaborate on the G20 discussion.

"I expressed our country's position at the call that there will be no sudden change in our reserve management policy," Choi said by telephone, referring to the country's heavy ownership of US bonds out of more than $300 billion in foreign reserves.

"There's no alternative (to US government bonds) that provides such stability and liquidity," he added

Copyright Reuters, 2011