North Korea on Sunday declared there was now a "state of war" with South Korea, the latest threat in a string of rhetoric that has many in the international community concerned about the possibility of fresh armed hostilities, Reuters reported.
"From this time on, the North-South relations will be entering the state of war and all issues raised between the North and the South will be handled accordingly," the state-controlled Korean Central News Agency said.
Pyongyang has delivered an escalating series of threats against South Korea and the United States after being hit by a new round of U.N. Security Council sanctions over the North's February nuclear test.
The South Korean Unification Ministry said "North Korea's statement today ... is not a new threat but is the continuation of provocative threats."
"I would note that despite the harsh rhetoric we are hearing from Pyongyang, we are not seeing changes to the North Korean military posture, such as large-scale mobilizations and positioning of forces," Reuters quoted White House spokesman Jay Carney as saying on Monday.
North Korean ruler Kim Jong Un on Sunday declared a "new strategic line" that focuses concurrently on enhancing nuclear weapons work and national economic development, the New York Times reported. At the same time, the official Workers' Party's governing Central Committee approved new precepts that affirm North Korea's nuclear weapons are not to be traded away for economic aid.
The South Korean Defense Ministry on Monday announced a new emergency "active deterrence" protocol that permits pre-emptive attacks on the North if it appears the South is on the verge of coming under a missile or nuclear assault, according to the Yonhap News Agency.
Defense Minister Kim Kwan-jin said Seoul would construct "an attack system to swiftly neutralize North Korea's nuclear and missile threats, while significantly improving our military's capability of surveillance and reconnaissance." Toward this end, the military would quicken its pace for fielding a "kill chain" system that can pinpoint, target, and eliminate strategic assets in the North, the ministry said.
The ministry also announced it would establish a domestic antimissile capability "at the earliest possible time," the Wall Street Journal reported. South Korea is already covered by U.S. extended deterrence, which includes missile defense. Detailed military plans might be finalized in October at yearly bilateral talks between the U.S. and South Korean heads of defense, Seoul said.
Meanwhile, the U.S. military dispatched radar-evading F-22 jets to the Korean Peninsula to take part in ongoing bilateral armed forces maneuvers that are meant to send a deterrent signal to Pyongyang, Reuters reported. U.S. nuclear-capable B-2 and B-52 bombers have already participated in the drills.
Indications that special precautions were taken to ensure no nuclear emissions seeped out from the underground chamber where February's atomic detonation took place have caused independent analysts and U.S. officials to speculate that North Korean bomb developers used a new warhead blueprint that utilizes weaponized uranium, the Washington Post reported on Monday. Previous tests featured plutonium-fueled devices.
It looks like Pyongyang "went to some length to try to contain releases" of radioactive gases, said an unidentified analyst who has been briefed about the U.S. evaluation of the North's third nuclear test. "One possible reason to try to contain releases is secrecy, so we don't know very much about their nuclear testing."