President Barack Obama says he expects broad agreement by G-20 nations on how to achieve balanced and sustainable economic growth.

Obama defended U.S. steps to climb out of its deep recession as prudent and stable. But he would not comment on the recent decision by the Federal Reserve to buy $600 billion in bonds that angered many trading partners.

Obama stressed that a strong United States economy is essential for a global recovery. He called the U.S. economy a "huge engine" that will impel other countries to grow.

Obama spoke during a joint news conference in Seoul with South Korean President Lee Myung-bak (lee myuhng bahk).