The head of South Korea's main opposition party called on the Seoul government Tuesday to expand its dialogue with North Korea, claiming only cooperation and exchanges can bring changes to the communist North.

"Raising the level of exchange and cooperation between the South and the North can change North Korea's way of thinking and also bring changes to the attitude of the North Korean regime itself," Rep. Sohn Hak-kyu of the Democratic Party said at a meeting with a civic activist group here.

"The incumbent government appears to be intent only on toppling North Korea, unable to even think about changing the North," he added.

Inter-Korean dialogue has been rare since the inauguration of the incumbent Lee Myung-bak government in 2008, though Seoul is now showing signs of efforts to resume dialogue with Pyongyang. President Lee's single five-year term ends early in 2013.

"Though only about one year is left in the administration's term, the government must start doing what it can even now," Sohn said.