1986 April: president Chun Doo-hwan 1989 November: president Roh Tae-woo 1995 March: president Kim Young-sam 1998 April: president Kim Dae-jung 2001 December: president Kim Dae-jung 2004 December: president Roh Moo-hyun 2006 February: Minister of Foreign Affairs and Trade Ban Ki-moon 2006 June: Minister of Foreign Affairs Ban Ki-moon 2009 April: president Lee Myung-bak (G20) 2013 April: Special envoy of the president, former prime minister Han Seung-soo (to attend the funeral of former British prime minister Margaret Thatcher) 2013 November: president Park Geun-hye 2014 December: Minister of Foreign Affairs Yun Byung-se. From the United Kingdom to South Korea: 1986 May: Prime Minister Margaret Thatcher 1992 November: Prince Charles and Princess Diana 1996 March: Prime Minister John Major 1997 April: Duke of Gloucester 1997 October: Duke of Kent 1999 April: Queen Elizabeth II 2000 October: Prime Minister Tony Blair 2003 July: Prime Minister Tony Blair 2001 April: Duke of York 2005 November: Duke of York 2006 October: Deputy Prime Minister John Prescott 2008 September: Duke of York 2008 December: G20 Special Envoy Timms 2009 October: Minister of Business, Innovation and Skills Peter Benjamin Mandelson 2010 November: Prime Minister David Cameron 2012 March: Deputy Prime Minister Clegg to attend Seoul Nuclear Security Summit 2013 October: Secretary of State for Foreign and Commonwealth Affairs William Hague (to attend Seoul Conference on Cyberspace 2013). United States The United States engaged in the decolonization of Korea (mainly in the South, with the Soviet Union engaged in North Korea) from Japan after World War II. After three years of military administration by the United States, the South Korean government was established. Upon the onset of the Korean War, U.S. forces were sent to defend South Korea against invasion by North Korea and later China. Following the Armistice, South Korea and the U.S. agreed to a "Mutual Defense Treaty", under which an attack on either party in the Pacific area would summon a response from both. In 1968, South Korea obliged the mutual defense treaty, by sending a large combat troop contingent to support the United States in the Vietnam War. The U.S. Eighth Army, Seventh Air Force, and U.S. Naval Forces Korea are stationed in South Korea. The two nations have strong economic, diplomatic, and military ties, although they have at times disagreed with regard to policies towards North Korea, and with regard to some of South Korea's industrial activities that involve usage of rocket or nuclear