U.S. President Barack Obama has welcomed the president of South Korea to the White House, beginning a day of events that will conclude with a state dinner.

On a rainy Thursday morning, South Korean President Lee Myung-bak arrived at the White House for the formal welcoming ceremony.

Mr. Obama described President Lee as a friend whose country has been an ally to the United States for six decades. He said the alliance between the nations has never been stronger.

For his part, Mr. Lee hailed the free trade agreement that the U.S. Congress passed late Wednesday.

The South Korean president called the deal an historic achievement that will open a new chapter between the countries, creating jobs and expanding mutual investment. He said it is a “win” for both countries.

The free trade deal is expected to be worth billions of dollars to both countries' economies.

Thursday's White House summit is expected to focus on North Korea and a possible new round of bilateral talks with Pyongyang.

Later Thursday, Mr. Lee will be afforded the rare honor of addressing a joint meeting of Congress, reflecting the growing economic and strategic relations between the United States and South Korea.

Mr. Lee was dining with President Obama at a Korean barbecue restaurant outside Washington when they received word late Wednesday that the U.S. Congress had approved the trade deal. The South Korean president now faces intense pressure to get approval of the agreement through his own country's legislature.

President Lee is to accompany President Obama on a visit Friday to a General Motors car plant in Detroit. Mr. Obama has said he would like to see Koreans driving U.S.-built cars the way many Americans drive Korean cars.

Wednesday, Mr. Lee visited the Pentagon for talks with Defense Secretary Leon Panetta and members of the Joint Chiefs of Staff. Mr. Lee said at the White House that he also visited the Korean War Veterans Memorial in Washington to pay tribute to the Americans who fought and died in the conflict.