Chinese and Indian soldiers salute at the opening ceremony of the Hand-in-Hand China-India Anti-Terrorism Joint Training Exercise in Pune, India, last year. [Photo/Xinhua]

Closer international cooperation is needed to combat the growing terrorist threat, a senior UN security chief has said.

Chen Weixiong, deputy executive director of the UN Security Council's Counter-Terrorism Committee Executive Directorate (CTED), also stressed that global and regional security concerns cannot be solved with military and law enforcement actions alone, but also require political involvement from international organizations.

The foreign terrorist fighters joining Islamic State forces in the Middle East post a particular threat, he warned.

"It's believed there are more than 25,000 foreign terrorist fighters from more than 100 countries," he said. "They have gone to Iraq and Syria to join (IS) using all possible routes and modes, and now some are (going) back to their countries of origin."

The global terrorism landscape had become more complex and more fluid as terrorist organizations, their affiliates and cells have pledge allegiance to IS.

Chen, who has been with the CTED for a decade, previously worked for China's Ministry of Foreign Affairs dealing with UN security matters. He said China has also been a victim of terrorism and faces serious threats, both inside its territory and to nationals and commercial interests overseas.

China has strength in a wide range of areas and has provided technical assistance to several states, while also being receptive to assistance and training, he said, adding that the country has advocated international cooperation in bringing terrorists to justice.

The UN plays a unique and important role in battling terrorism, given it has global legitimacy and a broad membership, said Mr. Chen, who explained that the organization has been trying to improve its coordination mechanism to meet emerging threats.

"How to create better coordination and synergy among all these entities to avoid duplication of programs and better measure the impact of donor-funded projects? This is something we have been taking steps in addressing," he added.

The Security Council adopted a resolution in September last year that condemned violent extremism and underscored the need to prevent travel and support of foreign terrorist fighters.

Various UN agencies work together on a counterterrorism missions, and Mr. Chen said CTED has been given a clear mandate by the Security Council to act as a monitor of state performance, facilitator of technical assistance, promoter of good practice, and a collaborator with other international players, such as member states, other UN entities, and international and regional organizations.

Chen said he is proud of his work at the UN and is glad to see more Chinese nationals taking part in various functions as well as at other specialized agencies. He said they are making a significant contribution to maintaining international peace and security, and promoting economic and social development.

"When it comes to counterterrorism, I believe that justice will conquer and prevail," he added.