An underground nuclear test by North Korea in February and joint U.S.-South Korean military drills sparked concern about the security on the Korean Peninsula.
Chung told lawmakers Thursday it was possible that North Korea may carry out another nuclear test but there are "no clear signs" of imminent activity. The government is keen in de-escalating the crisis.
"The (South Korean) government remains committed to maintaining the principle of denuclearization of the Korean Peninsula," he was quoted by the Yonhap news agency as saying.
South Korea said that, despite tensions, it doesn't see any indication that North Korea could equip a missile with a nuclear warhead.
Nevertheless, South Korean Defense Minister Kim Kwan-jin said preparations were under way to bolster national security.
"We are working on how to deal with North Korea's nuclear programs by devising two concepts. One is making tailored measures in case of its firing of nuclear missiles, and the other is how to detect, control and target its nuclear weapons," he said. "We are developing extended range interceptors."
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