"Since late 2008, relations between the United States and South Korea (known officially as the Republic of Korea, or ROK) have been arguably at their best state in decades. By the middle of 2010, in the view of many in the Obama Administration, South Korea had emerged as the United States' closest ally in East Asia. Of all the issues on the bilateral agenda, Congress has the most direct role to play in the proposed Korea-U.S. Free Trade Agreement (KORUS FTA). Congressional approval is necessary for the agreement to go into effect. In early December 2010, the two sides announced they had agreed on modifications to the original agreement, which was signed in 2007. South Korea accepted a range of U.S. demands designed to help the U.S. auto industry and received some concessions in return. In the United States, the supplementary deal appears to have changed the minds of many groups and members of Congress who previously had opposed the FTA, which is now expected to be presented to the 112th Congress in 2011. If Congress approves the agreement, it would be the United States' second largest FTA, after the North American Free Trade Agreement (NAFTA). U.S.-South Korean coordination over policy towards North Korea has been particularly close. The Obama and Lee Administrations have adopted a medium-to-longer-term policy of 'strategic patience' that involves three main elements: refusing to return to the Six-Party Talks without an assurance from North Korea that it would take 'irreversible steps' to denuclearize; gradually attempting to alter China's strategic assessment of North Korea; and using Pyongyang's provocations as opportunities to tighten sanctions against North Korean entities."
CRS Report for Congress, R41481