The 27th meeting of the Northeast Asia Cooperation Dialogue opened Tuesday in Singapore. 

Officials from China, Russia, the United States, South Korea and Japan are discussing regional security and the DPRK nuclear issue.

"It is mostly about the DPRK, obviously. How to bring about peaceful denuclearization. We're having good discussions,” said Joseph Yun, the US special representative for DPRK policy.

The discussions involve all the countries that were involved in the six-party talks, with the exception of the DPRK. 

The closed-door dialogue lasts for two days.