It took military leaders from both countries three days to hammer out the details of the agreement. Common radio frequencies were chosen for North and South Korean naval vessels, and a date was set - August 12 - for a new hot line between the naval commands to go into operation.

North and South Korean military officials first met in early June and agreed in principal on the measures. This week, they began to finalize the details.

The two countries are trying to avoid unintended clashes along their sea border. North Korea has never recognized an official maritime border off its western coast, and North Korean fishing and naval ships frequently cross into contested waters.

Lee Jung-hoon, a political scientist at Yonsei University in South Korea, says the pact comes just as the start of the annual crab-catching season increases the chances of conflicts at sea.

"There have been several clashes in that area, the most recent one led to the deaths of five south Korean naval officers, so it is important that the two sides come to some sort of agreement so that future naval clashes can be avoided," he said.

Military and civilian officials from two Koreas have held a series of meetings in the past few weeks to ease tensions along their border and strengthen bilateral relations. They have agreed to open cross-border transportation routes, remove propaganda signs and end propaganda broadcasts along their shared border, and exchange data on illegal fishing. South Korea also agreed to donate 400,000 pounds of rice to ease malnutrition in the communist North.

Professor Lee says the latest agreement is a positive step towards building trust between the two countries, although he warns that it does little to improve South Korea's security.

"I think the crux of the question is, is [the] North Korean military threat minimized at all over the past several years? Militarily and in terms of military posture, it's not changed at all," said Lee Jung-hoon.

South Korea's engagement with the North coincides with announced changes in the United State's military presence in the South. Washington said last week that it would withdraw about one-third of its 37,000 troops from South Korea, and pull the rest south, away from the border.

In response to the U.S. plans, the South Korean defense minister on Friday requested a 13 percent boost in defense spending for next year.