"China's role all along was very constructive, I had the privilege to thank Chinese President Xi (Jinping) for that," Piet de Klerk, chief negotiator of the third Nuclear Security Summit told Xinhua Wednesday.

"Ever since the preparations for this Summit started we worked closely together with China, " De Klerk started, "I visited China a few times and during the visit to China last November of Dutch Prime Minister Mark Rutte, who was chairing the summit, the Nuclear Security Summit was an important theme during the conversations."

"We always have attached great importance to China's participation. As Prime Minister Rutte said: 'A Summit without President Xi wouldn't be a real Summit'. China's role all along was very constructive," he said.

"On many nuclear security issues we share the views expressed by the Chinese president," De Klerk added. "It is important that nuclear security is put on a sustainable track with proper mechanisms."

The chief negotiator ended by saying that "President Xi's conclusion that all countries should work together to prevent and combat nuclear terrorism in all forms is very welcome. Strengthened international cooperation is in our view of crucial importance."