President Obama signed the legislation implementing the U.S.-South Korea Free Trade Agreement (KORUS FTA) on October 21, 2011 (P.L. 112-41), and the Korean National Assembly passed the agreement on November 22, 2011. The KORUS FTA entered into force on March 15, 2012. With the KORUS FTA now in force for over two years, focus has shifted from the debate over its passage to its implementation, economic impact, and effect on future U.S. FTAs. Some U.S. companies have argued that certain aspects of the KORUS agreement are not being implemented appropriately, citing issues related to rules of origin verification, express delivery shipments, data transfers, and pending auto regulations. In addition, a widening trade deficit with South Korea since the implementation of the agreement has led some observers to argue the agreement has not benefitted the U.S. economy, but it is difficult to distinguish the KORUS FTA's impact on U.S.- South Korea trade patterns from the impact of other economic variables. As the largest of the recently passed U.S. FTA's, perceptions of the KORUS FTA's economic impact and concerns over its implementation may influence congressional debate in the new FTAs now under negotiation, specifically the Trans-Pacific Partnership (TPP), which South Korea has signaled an interest in joining, and the Transatlantic Trade and Investment Partnership (T-TIP) between the United States and the European Union. The KORUS FTA is the second-largest U.S. FTA (next to NAFTA). In goods trade in 2013, South Korea was the sixth-largest trading partner of the United States, and the United States was South Korea's second-largest trading partner. The KORUS FTA covers a wide range of trade and investment issues and, therefore, could have significant economic implications for both the United States and South Korea. Congress approved the KORUS FTA implementing legislation using expedited procedures authorized by Trade Promotion Authority (TPA). Under TPA, which expired in 2007, the President had the discretion on when to submit the implementing legislation to Congress. The KORUS FTA was negotiated and signed on June 30, 2007, by President George W. Bush. However, President Bush did not submit the legislation because of differences with the Democratic leadership over treatment of autos and beef, among other issues. On December 3, 2010, after a series of negotiations, President Obama and South Korean President Lee announced that they had reached an agreement on addressing the outstanding issues related to the KORUS FTA. As a result, the final implementing legislation modified certain provisions of the 2007 agreement, primarily focused on trade in agriculture and autos.