S. Korea Assesses Supplies in Disputed Waters : Asia: Seoul vows to protect islands in Yellow Sea that fall under a zone unilaterally claimed by Pyongyang.

Local authorities began taking stock of food and other supplies for residents on five isolated Yellow Sea islands Friday after North Korea threatened to use military force to gain control over contested waters around them.

Kim Ki Soon, of the Wungjin county office that governs the islands, said his office was surveying the amount of emergency food and other daily necessities of 6,900 residents on the five islands scattered along North Korea’s southwestern coast, about 70 miles west of Seoul.

“We plan to supply food and other basic goods if and when ferry service to the islands is halted,” Kim said. Authorities reported normal ferry service to and from the islands Friday.

North Korea had announced a territorial claim to waters around the five islands on Thursday, saying that it would protect its sovereignty by “all means and measures.” After a similar claim in 1974, South Korean warships escorted ferries to and from the islands for several months.

South Korea countered Friday that its will to protect the zone was unshakable.

“We will defend the Northern Limit Line firmly and steadfastly,” South Korea’s office of the Joint Chiefs of Staff said in a statement. “If North Korea violates the line, we will consider it a provocation and will not condone it.”

The two Koreas are still technically at war, since their three-year war ended in 1953 with an armistice, not a peace treaty. The armistice never demarcated a sea border, and the American-led U.N. Command subsequently set the Northern Limit Line as a buffer to avoid armed clashes between the two sides.

The two countries largely honored the border until mid-June, when North Korean warships crossed it repeatedly, touching off the first naval clash between the nations since they were divided into the communist North and the capitalist South in 1945. About 30 North Korean sailors were believed to have died when their torpedo boat was hit and sunk.

Concern was rising that the claims of sovereignty might lead to new armed clashes.

“We don’t think the government would abandon us, but we are worried,” said Kim Kil Yeo, 51, a homemaker on one of the islands, Paek Ryong.

“I am concerned that we won’t be able to go fishing because of this situation,” said Shin Seung Won, 61, a resident of Young Pyong, another of the islands. “Fishing is our livelihood.”

After the June 15 skirmish, North Korea proposed that it and the United States, representing the U.N. Command, draw a new border farther south past the Northern Limit Line. The U.N. Command said a new border should be negotiated between the two Koreas.

The latest North Korean claim has worsened tensions caused by its threat to test-fire a new long-range missile. The nation sent shock waves through the region last year by test-firing a multistage missile that flew over Japan and landed in the Pacific Ocean.