South Korean President Lee Myung Bak appointed a new prime minister Thursday as part of a cabinet shuffle, according to dpa. The economist and former chancellor of Seoul National University, Chung Un Chan, was to replace Prime Minister Han Seung Soo. Chung, 63, is a well-known expert on economics, the President's Office in Seoul said. "His experience will allow him to more effectively assist the president and oversee the cabinet and to productively push forward centrist pragmatism and people-friendly policies," the office said. Chung has been critical of the government's economic policy. "What is important now is to assist the president in building a nation of a strong economy and unified society, and that is my goal," Chung said. His appointment needs parliamentary approval. Lee's changes to the government are believed to be targeted at pushing forward his reform programme. Changing prime ministers is not unusual in South Korea and the most important decisions are made by the head of state. Lee has been president since 2008. The conservative president also appointed General Kim Tae Young, the chairman of the Joint Chiefs of Staff, to be the new minister of defence. Lee changed the heads of the economics, justice, employment and equality ministries as well. Three of the ministerial posts went to deputies from the governing Grand National Party. A minister without portfolio position was created to be filled by a deputy from the ruling party.