South Korea will force North Korea to give up its nuclear programme based on firm defence readiness and international cooperation, the media reported on Tuesday.
South Korean President Park Geun-hye said this during her speech to commemorate the 97th anniversary of the Independence Movement against Japan's colonial rule in the Korean peninsula, Xinhua news agency reported.
"It became clear for existing responses to be unable to discourage North Korea's nuclear development," Park said, adding that if North Korea is left as it is, it will conduct fifth and sixth nuclear tests that will threaten stability in Asia, survival of Koreans and peace in the world.
North Korea carried out what it claimed to be its first hydrogen bomb test on January 6 and launched a long-range rocket using ballistic missile technology on February 7.
Tougher sanctions on North Korea are under discussion at the UN Security Council.
South Korea implemented its unilateral restrictions by closing down the Kaesong industrial zone, the factory park in the North Korean city of Kaesong.
Park said that pressures by Seoul and the international society on North Korea would continue unless it shows the intention to denuclearise.