South Korea should keep pressing North Korea to make Pyongyang abandon its nuclear ambitions, the country's top diplomat said Tuesday, adding that the focus should be placed on enforcing tough sanctions on Pyongyang until it leads to results.

"Things have become graver than ever before since the (North's) fourth nuclear test," Foreign Minister Yun Byung-se said during a parliamentary interpellation session. "We should be focused on sanctions in a way they can have more impact."

North Korea conducted its fourth nuclear test followed by a long-range missile launch earlier this year, which drew harsh condemnation from the international community.

The U.N. Security Council adopted the toughest ever resolution in March aimed at punishing the North for its provocative behavior.

"(I) think we will be able to make the North pay the price if we keep putting pressure on it in tandem with the U.N. Security Council-led effort on denuclearization," the policymaker said.

The minister noted that the top priority is to induce the North to change its "strategic calculus" and achieve denuclearization on the Korean Peninsula "as quickly as possible." (Yonhap)