South Korea's Unification Ministry has expressed deep regret over North Korea’s lack of response to Seoul’s offer for talks to discuss wage issues at the Gaeseong Industrial Complex.

Ministry spokesman Lim Byeong-cheol said in a statement on Monday that it's questionable whether the North has the will for the development of the complex as the two sides agreed.

In the statement, the ministry strongly criticized that the North’s unilateral decision to raise wages for its workers at the industrial park goes against an inter-Korean agreement which calls for joint operation of the complex. It added that the decision also violates a regulation that states wages should be discussed between the two Koreas every year.

The spokesman urged the North to swiftly respond to Seoul’s call for talks, while stressing that the Seoul government will take all necessary measures for the development of the industrial complex and the protection of South Korean firms operating at the complex.

On February 24, the North unilaterally informed Seoul that it will raise the minimum monthly salary of North Korean workers at Gaeseong from 70-point-35 dollars to 74 dollars beginning in March.