SEOUL -- The Seoul Defense Dialogue opened Wednesday with focus placed on regional and global security, the South Korean defense ministry said.

The three-day event, a vice ministerial-level regional security forum launched in 2012, has drawn about 250 defense officials and private security experts from 30 nations including China, the United States and Japan, and four international agencies such as the United Nations and the European Union.

Discussions will be held in three sessions on the unification of the Korean Peninsula and global security, analysis and management of maritime crisis in East Asia, and cyber security and defense cooperation, respectively, according to the ministry.

During the three days, bilateral meetings of participating countries will also be held along with a semi-multilateral meeting between China, the United States, Japan, Russia and Mongolia as well as South Korea.

This year's forum runs under the theme of "70 years after WWII, 70 years after division: challenges and hopes" as this year marks the 70th anniversary of the victory of the World War II and the divided Korean Peninsula.