A view of the East Room of White House where President Barack Obama and first lady Michelle Obama are hosting a state dinner for South Korean President Lee Myung-bak on Thursday, Oct. 13, 2011, in Washington. (AP Photo/Evan Vucci)
South Korean President Lee Myung-bak, left, shakes hands with Vice President Joe Biden after addressing a joint session of Congress at the Capitol, in Washington, Thursday, Oct. 13, 2011. (AP Photo/Cliff Owen)
South Korean President Lee Myung-bak addresses a joint session of Congress on Capitol Hill in Washington, Thursday, Oct. 13, 2011. (AP Photo/Cliff Owen)
Secretary of State Hillary Rodham Clinton, Vice President Joe Biden, and South Korean President Lee Myung-bak, toast each other during a luncheon at the State Department in Washington, Thursday, Oct. 13, 2011. (AP Photo/Ann Heisenfelt)
President Barack Obama welcomed South Korean President Lee Myung-bak, to a joint news conference in the East Room of the White House in Washington D.C., October 13, 2011 (Mary F. Calvert/Special to the Washington Times)
President Barack Obama and South Korean President Lee Myung-bak take part in a joint news conference, Thursday, Oct. 13, 2011, in the East Room of White House in Washington. (AP Photo/Evan Vucci)
President Barack Obama and South Korean President Lee Myung-bak take part in a joint news conference, Thursday, Oct. 13, 2011, in the East Room of White House in Washington. (AP Photo/Evan Vucci)
President Barack Obama and South Korean President Lee Myung-bak are welcomed by local school children during a rainy state arrival ceremony, Thursday, Oct. 13, 2011, on the South Lawn of the White House in Washington. (AP Photo/J. Scott Applewhite)
President Barack Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct. 13, 2011. (AP Photo/Evan Vucci)
President Barack Obama speaks as he welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct., 13, 2011. (AP Photo/Pablo Martinez Monsivais
President Barack Obama smiles as he welcomes South Korean President Lee Myung-bak during a rainy state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct. 13, 2011. (AP Photo/J. Scott Applewhite)
President Barack Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct., 13, 2011. (AP Photo/Pablo Martinez Monsivais)
President Barack Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct., 13, 2011. (AP Photo/Pablo Martinez Monsivais
President Barack Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington, Thursday, Oct., 13, 2011. (AP Photo/Pablo Martinez Monsivais
President Obama and South Korean President Lee Myung-bak are welcomed by local schoolchildren during a rainy state arrival ceremony on Thursday, Oct. 13, 2011, on the South Lawn of the White House in Washington. (AP Photo/J. Scott Applewhite)
President Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington on Thursday, Oct. 13, 2011. (AP Photo/Evan Vucci)
South Korean President Lee Myung-bak reaches out to local schoolchildren during a rainy state arrival ceremony with President Obama on Thursday, Oct. 13, 2011, on the South Lawn of the White House in Washington. (AP Photo/J. Scott Applewhite)
President Obama welcomes South Korean President Lee Myung-bak during a state arrival ceremony on the South Lawn of the White House in Washington on Thursday, Oct. 13, 2011. (AP Photo/Pablo Martinez Monsivais)