A long-running dispute over US access to RoK auto and beef markets was largely responsible for the failure, according to the White House.  

Obama tried to put a positive spin on the setback during a joint news conference with his RoK counterpart Lee Myung-bak. "We have asked our teams to work tirelessly in the coming days and weeks to get this completed, and we are confident that we will do so", he said. 

Lee has agreed to send a team to Washington to continue work on the trade pact. Among the hurdles negotiators are trying to overcome: Korean conglomerates which have kept a firm grasp on the union-strong country's marketplace, drawing complaints from foreign companies that have tried to do business there. 

Obama is in South Korea for the G-20 summit, which is meeting November 11 - 12 to try to stabilize the world's financial markets. His trip is part of a 10-day Asia tour that is aimed at strengthening the United States' trade and military ties with a region that has thrived economically.