Unification Minister Lee In-young expressed regret Thursday over North Korea's release of water from a border dam without giving South Korea prior notice earlier this week.

On Monday, the North partially opened the floodgates of Hwanggang Dam on the western inter-Korean border and sent water into the Imjin River, a move that put authorities here on alert against a potential rise in water levels in the South.

"I express my regrets over the recent unilateral measure to release dam water," Lee said at the start of a meeting of the Inter-Korean Exchange and Cooperation Council. "North Korea might have had difficulties of their own due to heavy rainfall, but I would like to stress they should have at least notified us prior to the release."

He urged the North to notify the South in whatever way possible.

"No matter how difficult the inter-Korean situation is politically and militarily, we need to restart dialogue immediately at least on issues related to the humanitarian field or the safety of the residents living near the border," he added.

Under an agreement signed between the two Koreas in October 2009, the North agreed to notify the South in advance of its plans to open the floodgates, following a deadly accident that killed six South Koreans after the North discharged water from Hwanggang Dam without notice.

The defense military said it is closely monitoring related moves in the North while sharing information with other government agencies.

"We are actively sharing information on the situation with other government agencies to prevent any damage to our people and troops," Joint Chiefs of Staff spokesperson Col. Kim Jun-rak said during a regular press briefing. (Yonhap)