SEOUL, South Korea — U.S. Secretary of State Wendy Sherman warned Tuesday of a strong response to North Korea’s first nuclear test explosion in almost five years. Sherman was traveling to Seoul to meet with Japanese and South Korean allies to discuss the growing standoff.

Officials from the U.S., South Korea and Japan have stated that North Korea is almost ready to carry out another nuclear test at Punggye-ri’s nuclear testing site. This northeastern town was last used for a test in September 2017. It claimed to have detonated an intercontinental ballistic missile-related thermonuclear weapon.

The Biden administration has pledged to press for international sanctions in the event that North Korea conducts a nuclear test. However, there are no prospects of meaningful new punitive actions with the United Nations Security Council split over Russia’s attack on Ukraine.

“Any nuclear attack would be in total violation of U.N. Security Council resolutions.” Sherman stated that there would be a prompt and forceful response to such an attack after meeting with Cho Hyun-dong, South Korea’s Vice Foreign Minister.

She said, “We continue to urge Pyongyang cease its destabilizing or provocative activities and choose to follow the path of diplomacy.”

Sherman and Cho will be meeting with Mori Takeo, the Japanese Vice Foreign Minister, on Wednesday to discuss the North Korean nuclear problem. Sherman’s visit to Asia was made after North Korea launched eight ballistic missiles at the sea on Sunday. This may have set a new record in single-day launches. It also extended a provocation streak in weapons testing this year, which included the first demonstrations of ICBMs in the country since 2017.

North Korean leader Kim Jong Un may further increase his brinkmanship and conduct its seventh nuclear test since 2006. Experts believe North Korea could test their ability to make small nuclear bombs. These could be used to cluster on a multiwarhead ICBM, or to fit on Kim’s growing range of short-range solid-fuel missiles. This would increase the threat to Japan and South Korea.

Rafael Mariano Grossi is the director general of International Atomic Energy Agency. He said Monday that there are indications of a passage at Punggye-ri’s testing ground being reopened. This could be in preparation for a nuclear bomb test.

Ned Price, spokesperson for the State Department, told reporters in Washington hours before Sherman’s meeting that North Korea might seek a seventh test.

Recent punitive actions taken by the Biden administration in response to North Korea’s recent weapons test have been largely symbolic and unilateral. Russia and China had vetoed an American-sponsored resolution which would have placed additional sanctions on North Korea for its May 25th ballistic test.

Price stated that he had called upon members of international community to become responsible stakeholders in U.N. Security Council, pointing out that the Council is a leading forum to address threats to international security and peace.

“Unilateral responses are not going to be the most attractive, nor even the most effective, response,” he stated, referring to South Korea’s official name, the Republic of Korea.

The launches of Sunday have not been reported by the North Korean state media. The launches came just after the U.S.-based aircraft carrier Ronald Reagan completed a three day naval drill in the Philippine Sea on Saturday. This was apparently their first joint drill in that area since November 2017. As the two countries seek to improve their defense exercises against North Korean threats,

North Korea has always condemned the combined military exercises of its allies as invasion rehearsals. It often countered these drills with its own missile drills. In 2016, and 2017, short-range launches were used to simulate nuclear attacks on South Korean ports.

The United States conducted sperate missile drills with Japan, South Korea and South Korea in response to the latest North Korean rocket launches.

Since 2019, nuclear talks between Washington, Pyongyang and Iran have been stalled due to disagreements over exchanging crippling U.S. sanctions for North’s disarmament efforts.

Kim is not willing to give up his arsenal, which he considers his best guarantee of survival, despite facing severe challenges at home, such as a declining economy and a COVID-19 epidemic.

Experts say that his government has rejected open-ended offers from the Biden administration and is determined to convert the dormant negotiations on denuclearization into a mutual arms reduction process.