Humbled by elections at home, U.S. President Barack Obama Thursday endured a sobering test of his power abroad, unable to close a trade deal with South Korea and thrown on the defensive about America's approach to global economic worries.

According to An Associated Press report, from halfway around the world, Obama admonished both friends and foes back in Washington to "tell the truth" about the pain of cutting the government's huge spending deficits.

In Seoul on Thursday, on a stage meant to salute triumph, Obama could not announce a free-trade pact with his ally and host, South Korean President Lee Myung-bak. It was an embarrassing setback given Obama's high expectations and his desire to deliver more jobs for frustrated Americans at home.

"We want this to be done in a matter of weeks," Obama said of the deal, insisting that trade chiefs will keep working to get a pact that will survive political tests in both countries. Lee called the hang-ups merely technical, and both leaders said allowing extra time was the smart way to deal with obstacles over U.S. beef and autos.

Yet the upshot was underwhelming: a determined call for more negotiation, said the AP analysis.

As the pleasantries of the G-20 economic summit of world leaders began, Obama was still defending a decision that was not his: the Federal Reserve's move to flood $600 billion of cash into the sluggish American economy to drive down interest rates, spur lending and boost spending. Angry trading partners say the Fed intervention undervalues the dollar and gives U.S. exporters an edge.

In the latest of the short news conferences he's sprinkling across Asia, Obama was challenged about feeling isolated over U.S. monetary policy. He turned around the notion by predicting good news will emerge: a broad agreement by all nations on a plan for the balanced, stable growth he is championing.

Yet when Lee was asked if there were dangerous implications in the U.S. approach, his first response was no comfort: "That kind of question should be asked to me when President Obama is not standing right next to me."

Getting out of Washington for 10 days has had a duel effect on Obama. The timing has given him an escape from the Beltway bubble and offered up memorable moments: dancing with children in India, and reliving boyhood stories in Indonesia.