South and North Korea have drafted a tentative agreement on maritime cooperation at the fourth round of such talks at North's border city of Gaesong.

The agreement calls for the two sides to open their territorial waters for the safe passage of each other's commercial vessels.

Under the agreement, South Korean vessels will be allowed to directly communicate with the South while traveling in North Korean waters. But North Korean merchant ships would not be allowed to pass the shipping route between the south coast and the Jeju Island. South Korea is opposed to opening the Jeju channel for security reasons.

The two Koreas agreed to exchange related documents, at the earliest date, to formally sign the maritime accord at the next inter-Korean economic cooperation committee meeting.