Military and defense leaders are among those attending the forum. CGTN spoke with Serbian Defense Minister Aleksandar VU-lin, who says all countries are threatened by fundamentalism, separatism and unilateralism, and they need to work together to protect international law and order.

ALEKSANDAR VULIN SERBIAN DEFENSE MINISTER "The biggest challenge worldwide is that international laws are not abided by. In this regard, Serbia's rights are usually violated. If we do not abide by international law, it's hard to solve problems. If we do not restore the dignity of international law, then no country can find a solution on its own. Therefore, I hope that we can find solutions together in a peaceful way."

ZHENG YIBING CGTN REPORTER "US president Donald Trump says the US will withdraw from its long-standing nuclear arms treaty with Russia. What is your assessment of that?"

ALEKSANDAR VULIN SERBIAN DEFENSE MINISTER "Any suspension of dialogue or negotiations would be cause for concern. We would rather talk for 100 years than wage a war for even one day. Any violation of an international deal would worry us. If it happens or if a big power withdraws from a deal, we would be worried. I hope the United States and other powers can get back to the conference table and give other countries hope."