North Korea has demanded a raise for its workers at the Gaesong Industrial Complex for the first time since South Korean firms relocated to the park in 2004.

The Unification Ministry said Tuesday that the North requested early last month a four-percent increase of the basic monthly wage of 50 dollars.

The North also requested that South Korean employers pay staff representatives and high-ranking employees salaries commensurate with their job titles.

In January, the employers raised the daily pay from a dollar-64 cents to two dollars at the North’s request.

The ministry will first discuss the raise with employers and then North Korean authorities to minimize the burden on South Korean companies in the complex.