Mr. Han, who served as prime minister from 2007 to 2008, had been expected to stay in Washington through the December presidential election.
However, he told friends privately that he intended to step down after Congress and the South Korean legislature approved a U.S.-South Korean free-trade deal last year.
Foreign visitors in Washington this week include:
• Alexander Stubb, Finland’s minister for European affairs and foreign trade, who addresses the Brookings Institution.
• Prime Minister David Cameron of Britain, who meets with President Obama.
• Irina Bokova, director-general of UNESCO, who addresses the Women’s Foreign Policy Group.
• Alberto Aleman Zubieta, administrator of the Panama Canal Authority, who addresses the Inter-American Dialogue.
• Janos Horvath, the most senior member of the Hungarian parliament, who addresses guests of the Hungarian Embassy about legislative reform in his country.
• Call Embassy Row at 202/636-3297 or email firstname.lastname@example.org. The column is published on Mondays, Wednesdays and Fridays.