By Kim Rahn
North Korea appears to have succeeded in miniaturizing a nuclear warhead, Defense Minister Song Young-moo said Monday, a day after Pyongyang conducted its sixth nuclear test.
It also suspected the North will soon carry out its third test of an intercontinental ballistic missile (ICBM).
"We assume that North Korea has secured the capability to miniaturize its nuclear warhead to less than 500 kilograms through the six tests," Song said during a National Assembly session.
He added the government presumes the warhead is small enough to be mounted on an ICBM.
After conducting its sixth nuclear test Sunday, Pyongyang claimed it had developed a hydrogen bomb that can be mounted on its new ICBM. North Korea has test-fired two such missiles so far, July 4 and 28, claiming the long-range missile can strike the U.S. mainland.
The ministry and the National Intelligence Service (NIS) said they had detected signs of North Korea preparing for another ICBM launch.
According to the NIS, it is likely the North will carry this out around its Foundation Day, Sept. 9, or the anniversary of its Communist Party, Oct. 10.
It said there is a chance Pyongyang will fire an ICBM into the Pacific Ocean on either of the days using a regular trajectory rather than the high-angle one it has used to date.
The NIS also said Sunday's test was conducted at the second shaft of the North's nuclear test site in Punggye-ri, North Hamgyong Province, and additional tests are possible at any time because the third and fourth shafts have also been prepared.
It estimated the explosion yield of the nuclear test at about 50 kilotons, five times stronger than the North's fifth test about a year ago, but added it is examining whether it was really a hydrogen bomb or an enhanced nuclear weapon.
The defense ministry said it is consulting with the U.S. about deploying a nuclear-powered aircraft carrier and strategic bombers here. "We asked the U.S. to regularly deploy assets of extended deterrence such as aircraft carriers and nuclear-powered submarines," Minister Song said.
He said participants of the National Security Council presided over by President Moon Jae-in right after the test Sunday agreed that it was time to focus on pressure rather than the peace overture proposed in Moon's Berlin speech in July.
Live-fire drill targets nuclear test site
In a direct response to the nuclear test, the military conducted a live-fire missile drill Monday, according to the Joint Chiefs of Staff (JCS).
"We conducted a combined live-fire exercise early in the morning, as a strong warning following Pyongyang's sixth nuclear test," the JCS said in a press release.
The military used a Hyunmoo-2A surface-to-surface missile and the F-15K's SLAM-ER air-launched cruise missile, which hit the designated targets in the East Sea accurately.
"The missiles were fired at targets which were set in accordance with the distance to the nuclear test site in Punggye-ri," JCS spokesman Roh Jae-cheon said. "We showed the capability of pinpoint strikes at the origin of provocations and the enemy's leadership."
The Hyunmoo-2A missile's range is about 300 kilometers, while Punggye-ri is about 280 kilometers away from Sokcho, Gangwon Province, where the exercise was conducted.
The weight of the missile's warhead was 1.5 tons, which can destroy underground bunkers in North Korea, according to the JCS. The SLAM-ER, with the capability of pinpoint strikes, can put all of North Korea within range if launched near the Military Demarcation Line.
The South Korean and the U.S. military authorities also plan to stage a joint show-of-force soon.
Talks with Abe
In the meantime, President Moon and Japanese Prime Minister Shinzo Abe called for a whole new level of countermeasures against North Korea's nuclear ambitions.
During a 20-minute phone conversation, the two leaders expressed serious concerns about the power of the North's hydrogen bomb and the possible use of it on an ICBM as Pyongyang has threatened.
"They agreed that the two nations and the international community need to cooperate on the strongest pressure and sanctions," presidential spokesman Park Soo-hyun said. "They urged a whole new level of practical and strongest-ever measures, which will put real pressure on Pyongyang."
Moon and Abe will first seek a new round of sanctions by the United Nations Security Council (UNSC), which can make the North return to negotiations, Park said.
Besides the heads of the states, National Security Office chief Chung Eui-yong and U.S. President Donald Trump's security adviser H.R. McMaster had a phone talk to share information about the test. They agreed that the countries would take all future actions based on close and transparent consultation with each other.
Chung and McMaster have had three phone calls in 24 hours since the test Sunday afternoon.
Top nuclear envoys of South Korea, Japan and the U.S. also agreed on stern countermeasures against the North's nuclear threats.
Kim Hong-kyun, the special representative for the Korean Peninsula peace and security affairs at the foreign ministry, had respective phone calls with his Japanese and U.S. counterparts, Kenji Kanasugi and Joseph Yun, Sunday evening, according to the foreign ministry, and talked about strongest possible actions against Pyongyang.
Seoul and Washington also decided to hold an annual meeting of director-level officials from foreign and defense ministries as part of the Extended Deterrence Strategy and Consultation Group (EDSCG), which was launched last October.
The EDSCG will operate on two tracks ― an annual working-level session led by director-level officials and a biannual executive session led by vice minister-level officials. Every two years when the executive session is not held, a so-called 2+2 meeting of foreign and defense ministers will take place, according to a joint press release from the two countries.