HONG KONG (Yonhap News) -- A nuclear security summit to be held in Seoul in March may send an implicit message to nuclear-ambitious North Korea, although the secretive nation's nuclear issue is not on the summit agenda, a top official said Monday.

The second Nuclear Security Summit is slated to take place in Seoul from March 26-27. The main goal of the summit, which follows the inaugural one in the United States in 2010, is aimed at preventing nuclear terrorism.

"We do not plan to officially discuss Iranian and North Korean issues (during the summit)," Hahn Choong-hee, sous-sherpa and spokesman of the preparatory secretariat for the Seoul summit, told reporters in Hong Kong.

"However, the summit itself may send a message to North Korea."

Talks aimed to dismantle North Korea's nuclear arsenal through economic and political incentives have been stalled since December 2008 due to North Korea's boycott and tensions over its two deadly attacks on the South last year. The talks involve six countries -- the two Koreas, the United States, China, Japan and Russia.

The March summit comes as neighboring countries carefully watch North Korea, which is now led by Kim Jong-un, the youngest son of recently deceased former leader Kim Jong-il.

Jong-un's succession of the North Korean leadership has raised fresh concerns over the North's nuclear program.

The Seoul summit will be attended by top leaders from about 50 countries including the United States, Russia, China, Japan, Britain and France.

Earlier this month, negotiators from about 50 nations scheduled to participate in March's nuclear security summit reached an agreement "in principle" to minimize the civilian use of highly-enrichment uranium (HEU).

The key topics for the Seoul summit include how to protect vulnerable radioactive materials worldwide to prevent terrorists from using them to make crude nuclear bombs, South Korean officials said. Topics also include "practical and concrete" ways to prevent the threat of nuclear terrorism and ensure the safety of atomic energy.

The summit is expected to announce a so-called "Seoul Communiqué," which will be based on the agreements reached during the two-day meeting.