The Unification Ministry in Seoul has explained to South Korean firms doing business with North Korea the measures the government is taking against Pyongyang.

Unification Vice Minister Eom Jong-sik on Tuesday explained the measures to the heads of 14 firms doing business in the North. Eom reportedly asked for the firms’ understanding on the measures that are being taken in response to North Korea’s sinking of the “Cheonan” naval vessel.

In a separate move, the government also plans to provide explanations about the response measures to private organizations that are conducting humanitarian assistance projects in the impoverished North.

Earlier on Monday, the Unification Ministry declared a full halt to inter-Korean trade with the exception of trade and exchanges related to the Gaeseong Industrial Complex in the North. The ministry also banned visits by South Koreans to the North and put on hold all projects that help the North except for those involving humanitarian assistance for North Korean infants and people in need.

According to the ministry, there are some 200 firms that have manufacturing deals with the North and some 580 firms that trade with the North.