Foreign Minister Yun Byung-se Friday called for closer global cooperation against cyber-attacks, citing the hacking of Sony Pictures and South Korea's nuclear power plant operator by North Korea.

After their own investigations, the U.S. and South Korea announced that North Korea was behind the series of online attacks.

The communist nation denied the allegations.

The two cases "vividly" showed the gravity of the cyber threat, Yun said while delivering a keynote speech at the Global Conference on Cyberspace underway in the Hague, the Netherlands.

"We need robust, effective partnerships for countering cyber-attacks and cybercrimes," he said, according to a transcript released by the foreign ministry. He did not directly mention North Korea.

Yun attended the two-day session not only as Seoul's top diplomat but also as the chair of the previous meeting held in Seoul in 2013.

"Internationally, we should set up prompt and timely judicial cooperation and information sharing between countries, because time is of the essence in responding to cyber-attacks," Yun stressed.

"In particular, states should actively work together in responding to cyber-attacks on critical infrastructure and tracking down the perpetrators."

More than 1,700 officials and experts from around 90 countries and 20 international organizations and civic groups joined the Hague meeting.

On the sidelines of the forum, Yun had bilateral meetings with his counterparts from the EU, Australia, the Netherlands, Serbia and Ukraine. (Yonhap)