The UN Security Council has set out to craft a fresh set of tougher punitive measures over North Korea’s latest nuclear test, while Seoul and Washington mull independent sanctions to deepen the North’s isolation and further tighten the economic screws.

The 15-member council convened an emergency session in New York on Friday, hours after the communist state carried out its fifth underground blast, which demonstrated the strongest explosive power yet. The body issued a press statement condemning the act, vowing to tighten its squeeze through a new resolution. 

South Korea has begun coordination on international measures with the US, Japan and other countries, and is stepping up diplomatic efforts to bring on board Russia and China, the North’s diplomatic backers and permanent members of the UNSC.

The allies are likely to call for the envisioned resolution to include an additional export ban on items and an expanded blacklist of North Korean personnel and entities suspected to have been involved in its nuclear and missile programs. 

The Foreign Ministry here is known to have handed over a list of potential steps through its UN representative in New York.

Seoul is also seeking to impose further standalone sanctions as it did following Pyongyang’s last atomic and long-range missile experiments earlier this year.

“It’s too early to assume what the upcoming resolution would be about, but we think that it should first and foremost take into account the factors that we could not consider in making Resolution 2270,” a senior ministry official told reporters on Sunday, referring to the document passed in March after the North’s fourth nuclear test.

“It should also be able to plug any perceived loopholes stemming from the last resolution, as well as embrace new factors we’ve found out throughout its implementation over the last six months.”

Regarding individual sanctions, the government will explore various options on its own and also through consultations with Washington, Tokyo and other partners so as to boost synergy, the official said.

On the military front, the US plans to dispatch a nuclear-powered aircraft carrier to South Korea next month in a show of force to deter further military provocations, a ministry official here said.

The USS Ronald Reagan (CVN-76), the flagship of the Yokosuka, Japan-based Carrier Strike Group Five of the US Navy, will sail to South Korea’s Yellow and South seas to participate in a joint naval exercise with South Korea, slated for Oct. 10-15, the official said.

The exercise will focus on training the allies’ naval forces on joint precision attacks on North Korea’s key military facilities and the regime’s leadership, attacks that would be launched in the event of a war with the communist country. Called a floating air base, the vessel is capable of carrying some 80 combat fighters and aircraft, as well as about 5,400 crewmen. Powered by two nuclear reactors, the USS Ronald Reagan is part of powerful deterrence assets the US maintains against North Korea’s military threats.

Other warships under the Carrier Strike Group Five will accompany the USS Ronald Reagan to the drills, the official said, including the USS Curtis Wilbur (DDG-54), USS John S. McCain (DDG-56), USS Fitzgerald (DDG-62), USS Stethem (DDG-63) and USS Barry (DDG-52) destroyers.

Sources said the US will dispatch a strategic bomber, possibly the B-2, to South Korea as early as Monday from the Andersen Air Force Base in Guam.

“The deployment of a strategic bomber on the Korean Peninsula alone mounts a considerable level of pressure on North Korea,” a military official said.

The North carried out the latest nuclear explosion on its founding anniversary Friday, just eight months after its fourth test in January. South Korea’s Joint Chiefs of Staff assessed the nuclear test at the Punggye-ri nuclear site as the North’s biggest test to date, with the device giving off an explosive yield reaching 10 kilotons. The yield was higher than the estimated 6 kilotons detected in January’s nuclear test.

The UNSC on Friday strongly condemned North Korea’s fifth nuclear test and pledged to begin work immediately to put together a new resolution of sanctions punishing the communist nation.

“The members of the Security Council strongly condemned this test, which is a clear violation and a flagrant disregard of Security Council resolution,” Security Council President and New Zealand Ambassador Gerard van Bohemen told reporters after urgent discussions, reading a press statement.

“In line with this commitment and the gravity of this violation, the members of the Security Council will begin work immediately on appropriate measures under Article 41 in a Security Council resolution.”

It could take weeks to put together new sanctions. It took about two months for the council to adopt a new resolution following the North’s fourth nuclear test in January.

On Sunday, a top US envoy said Washington and Tokyo are also seeking “the strongest possible” measures against North Korea.

Sung Kim, the US State Department’s special representative for North Korea policy, suggested that the US may launch its own sanctions in response to “the provocative and unacceptable behavior by the North Koreans” after his meeting with Japanese counterpart Kenji Kanasugi.

Kanasugi said Seoul, Tokyo and Washington would continue to work together.

“We agreed to continue Japan-US and Japan-US-South Korea cooperation ... as we work toward an adoption of a new UN Security Council sanction that will include further sanction measures against North Korea,” he said in a statement.

Kim added that Washington’s “dialogue” with Beijing over the crisis will continue.

“We continue to work together to urge China to implement existing Security Council resolutions ... and to work with us to make sure North Korea’s behavior and their deliberation change in a more productive and positive direction,” Kim said.

After the North’s fourth nuclear test in January, the Security Council adopted the fifth and toughest-ever sanctions on the North, including mandatory inspection of all cargo going in and out of the North and banning exports of coal and other mineral resources.

Cooperation from China is key as the country is one of the veto-holding permanent members of the Security Council, along with Britain, France, Russia and the US.

China is North Korea’s top trading partner and responsible for the isolated nation’s energy needs. But Beijing has long feared that pressuring Pyongyang too hard could lead to its collapse and bring about instability on its border with China and the ultimate emergence of a pro-US nation, according to analysts.

After the UN meeting, China’s Ambassador Liu Jieyi avoided directly answering questions about Beijing’s sanctions commitment.

“We are opposed to testing and we believe that it is more urgent than ever to work together to ensure denuclearization of the Korean Peninsula,” Liu said. “All sides should refrain from mutual provocation and any action that might exacerbate the situation.”

Seoul and Beijing also discussed measures, according to the Foreign Ministry here on Saturday through the top nuclear envoys.

Kim Hong-kyun, Seoul’s special representative for Korean Peninsula Peace and Security Affairs at the ministry, spoke with his Chinese counterpart Wu Dawei on the phone.

“Both agreed to keep open the lines of communication and cooperate with each other in regards to the North’s nuclear issue, including future countermeasures,” the ministry said in a press release.

During the talks, Wu noted that China will never recognize North Korea as a nuclear state, nor will it condone the country holding nuclear weapons. He also said that Beijing stands firm on denuclearization, peace and stability on the Korean Peninsula.

Since March when the toughest-yet sanctions resolution was adopted, North Korea has carried out 21 ballistic missile launches.

On Saturday, South Korean Foreign Minister Yun Byung-se said he will urge cooperation in formulating a new set of sanctions against the communist state as he attends the week-long UN General Assembly meeting starting Saturday.

During his stay in New York, the country’s top diplomat will hold a meeting with his counterparts from the US and Japan to discuss how to impose stronger sanctions against Pyongyang, the ministry said. Yun is also to deliver a speech at the UN General Assembly meeting on Sept. 23.

Meanwhile, North Korea said Sunday that the US’ push for sanctions was “laughable” and the country would continue to strengthen its nuclear power.

“The group of (US President Barack) Obama’s running around and talking about meaningless sanctions until today is highly laughable,” the state-run KCNA news agency cited a Foreign Ministry spokesman as saying in a statement.

Earlier on Saturday, the North’s ceremonial head of state Kim Yong-nam vowed the reclusive country will increase its presence in international society to meet its “status as a nuclear power,” according to the North‘s state-run Korean Central News Agency.

Kim, the president of the Presidium of the Supreme People’s Assembly, said “(North Korea) will secure the world peace and safety and continue to expand and develop international relations in a way that fits its status as a nuclear powerhouse.”

By Shin Hyon-hee and news reports