North Korea has fired two short-range missiles into the Sea of Japan, also known as the East Sea, in its latest show of force against ongoing US-South Korea military exercises, increasing tensions on the Korean Peninsula.
The reclusive state yesterday also declared all cross-border economic agreements null and void and voiced intentions to sell off assets left behind by South Korean companies in shuttered joint projects. This was a tit-for-tat move against unilateral sanctions imposed by South Korea on Tuesday over the North's recent missile test and rocket launch.
South Korea's Unification Ministry condemned the North's announcement, calling it a "provocative action that cannot be overlooked". "North Korea must not damage valuable properties of our people and will have to take full responsibility for its behaviour," the ministry said in a statement.
South Korean President Park Geun Hye called for national unity in a speech yesterday, urging the people to remain united to better cope with the security crisis.
The North's move came as the United States said it was deploying three long-range stealth bombers capable of carrying nuclear weapons for the ongoing exercises, said to be the largest in recent years.
China, for its part, urged restraint, with Foreign Ministry spokesman Hong Lei asking the relevant parties to "stop these provocative words and actions".
Hours after the missile firing yesterday, Pyongyang's reunification committee said the state will "nullify all agreements adopted by North and South Korea on economic cooperation and exchange programmes".
It said North Korea will also "completely liquidate all assets of South Korean firms and related institutions left behind in our region", referring to the joint Mount Kumgang tourism resort, closed since 2008, and the Kaesong joint industrial complex, which was shut down abruptly last month.
Experts said the message is clear that both Koreas want to cut off all ties and cease all dialogue, and the situation is unlikely to improve until Ms Park's term ends next year.
Seoul has maintained a hardline approach towards Pyongyang since the latter conducted its fourth nuclear test on Jan 6 and Seoul made the first move to close Kaesong.
The period of good relations and reconciliation is "almost over", said Dr Choi Kang, vice-president of The Asan Institute for Policy Studies. He warned that a "big storm" looms ahead, and the two Koreas might exchange fire late next month when the US-South Korea exercises end.
Dr Paik Hak Soon, director of the Centre for North Korean Studies at the Sejong Institute, said North Korea is retaliating against the exercises by taking an offensive stance.
He cited mock pre-emptive strikes on the North and decapitation raids on its leader, Mr Kim Jong Un. "So North Korea responded with heightened threats and positioning its army to launch pre-emptive strikes as well," he said.
There is talk that South Korea's government is fuelling inter-Korean tensions to win votes in next month's legislative polls. "The bigger the North Korean threat, the more likely people will vote for the ruling party," Dr Paik said.
As for the North's actions, experts said they are to pressure Seoul, the US and the United Nations to lift sanctions and restart talks. "Kim Jong Un can't just sit around and wait - he has to show his people his leadership and try to break through to the UN by increasing tensions," said Dr Choi.