BEIJING, Nov. 16 (Xinhua) -- More than 60 defense studies experts from 21 nations attended a forum in Beijing on Friday to discuss security in the Asia-Pacific region.

The fourth Xiangshan Forum, a bi-yearly event organized by the China Association for Military Science to promote exchanges of opinions among defense scholars from around the world, kicked off in Beijing Friday.

Running under the theme of "Asia-Pacific Security: New Challenges and New Ideas," the three-day event will feature discussions on situation assessment and outlook, regional cooperation in space security and Internet safety and ways to boost strategic mutual trust in the region.

The forum was held first in 2006, and then in 2008 and in 2010.