President Obama and South Korean President Lee Myong-bak spoke this evening by telephone as part of their ongoing consultations on the full range of U.S.-ROK alliance issues. President Lee provided an update on the status of the investigation into the sinking of the ROK naval vessel Cheonan in which 46 Korean sailors lost their lives. He expressed appreciation on behalf of the Korean people for U.S. support in the Cheonan rescue and salvage operations, as well as for the participation of U.S. experts in the international inquiry. The two leaders emphasized the importance of obtaining a full accounting of the event and committed to follow the facts of the investigation wherever they lead. They also pledged their utmost efforts to ensure the security of the Republic of Korea, its armed forces, territory and its people. President Obama reaffirmed the strong and unwavering commitment of the United States to the defense and the well-being of its close friend and ally, the Republic of Korea.
President Obama and President Lee reiterated that North Korea must live up to its commitment to eliminate its nuclear-weapons program, comply with its international obligations under relevant U.N. Security Council resolutions, and put an end to belligerent behavior towards its neighbors. President Obama confirmed that Secretary Clinton would visit Seoul for consultations next week and that the defense and foreign ministers of the two countries would hold their first-ever "Two plus Two" meeting in July. Presidents Obama and Lee agreed to remain in close touch, and to meet at the time of the G-20 meeting in Canada in June.
Barack Obama, Readout of the President's Call with President Lee of the Republic of Korea Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/290371