SEOUL, South Korea — North Korea cut off the last remaining military hot lines with South Korea on Wednesday, accusing President Park Geun-hye of South Korea of pursuing the same hard-line policy of her predecessor that the North blamed for a prolonged chill in inter-Korean relations.

Amid tensions over the North’s third nuclear test last month and ensuing United Nations sanctions, North Korea had already shut down Red Cross hot lines with South Korea and a communication line with the American military command in South Korea. But the North’s decision to cut off military hot lines with South Korea on Wednesday was taken more seriously in Seoul because the two Koreas have used those four telephone lines to control daily cross-border traffic of workers and cargo traveling to the North Korean border town of Kaesong.

The two countries run a joint industrial park at Kaesong, the last symbol of inter-Korean cooperation that has survived the political tensions of recent years. Seoul officials said 887 South Korean workers were in Kaesong on Wednesday. The traffic was running normally on Wednesday and Thursday morning, with long lines of trucks crawling through the border crossing, South Korean officials said, indicating that the North Korean military did not go so far as to stop cross-border economic exchanges.

“There do not exist any dialogue channel and communications means between the D.P.R.K. and the U.S. and between the North and the South,” said a North Korean statement sent to the South Korean military by telephone and later carried by the North’s official Korean Central News Agency. “Not words but only arms will work on the U.S. and the South Korean puppet forces.”