Statement by Minister-Counsellor Mr. Nobuyuki KIKUCHI at the 66th session of Working Group B
2026/3/9
Mr. Chair, distinguished delegates,
At the outset, Japan offers its heartfelt gratitude to the Chair of Working Group B, to the task leaders, to the chairs of the expert meetings, and to the Provisional Technical Secretariat, whose steady labor has prepared the ground upon which we now stand.
Thirty years have passed since the CTBT was opened for signature. This solemn milestone meets us in the same year as the NPT Review Conference. Yet we gather in unsettled times. Trust among nations is strained; strategic dangers grow sharper and less predictable. In such an hour, the CTBT is no distant ideal. It is a living shield. For Japan, it remains a practical and steadfast pillar of the global regime for disarmament and non-proliferation.
That pillar stands firm because of its verification regime—above all, the International Monitoring System and the International Data Centre. These are not mere instruments of science. They are the means by which the will of the international community is made visible, by which solemn promises are tested and proven in fact.
Even before entry into force, our duty is clear. Verification must grow stronger as risks grow greater. Within the Preparatory Commission, we must deepen our capacity for detection, refine our collection of data, and sharpen our analysis. The knowledge assembled in this Working Group, joined with the advancing technologies of our age, must be brought fully to bear.
Yet machines and methods alone will not suffice. States Signatories must actively use their National Data Centres to judge whether events constitute nuclear tests. Relevant data should be shared swiftly and transparently. Where provision of data remains lacking, it must be improved in earnest. Such openness is not a courtesy; it is the lifeblood of the Treaty’s credibility and the safeguard of its very purpose.
We do not ignore the strain of financial pressures. To sustain the International Monitoring System—the very heart of verification—grows ever more demanding. Its maintenance is not only an urgent task requiring immediate attention, but also a responsibility that demands a medium- to long-term vision to ensure its enduring resilience and effectiveness. But it is in times of constraint that commitment is most truly measured. Japan calls upon all States Signatories to pursue practical solutions and to secure the sustainability of the IMS.
Capacity building, too, is essential. Since 1995, Japan has conducted the Global Seismological Observation Training Course through JICA with the support of Building Research Institute. This year, eight trainees joined, bringing the number of participants to more than 300 from some 80 countries. By strengthening the analytical and operational power of National Data Centres, we reinforce the Treaty’s global detection network and deepen the confidence we share.
Regarding On-Site Inspection, Japan welcomes the forthcoming Integrated Field Exercise 2026 and expresses its appreciation to the Government of Namibia for hosting it.
Mr. Chair,
On North Korea, Japan recalls with deep concern that within the three decades since the CTBT’s opening for signature, North Korea has conducted six nuclear tests and is a core mandate issue of the CTBT and hence should continue to be taken up during the Prep Com and Working Groups. North Korea’s nuclear issue is not merely a regional concern but a global challenge that strikes at the very core of the CTBT’s purpose and verification mandate.
Japan expresses serious concerns over the advancement of North Korea’s nuclear and missile development. We urge North Korea not to conduct any destabilizing or provocative actions, including a nuclear test. Japan also urges North Korea to comply with its obligations under the relevant UN Security Council resolutions, to return to full compliance with the NPT and to sign and ratify the CTBT at the earliest possible date. Japan reiterates its firm dedication to achieving the complete denuclearization of North Korea in accordance with UNSC resolutions and remains resolute in upholding its crucial responsibilities toward this goal.
Mr. Chair,
Thirty years on, the CTBT is unfinished work—yet it is no empty vow. Its verification regime functions. Its norm endures. Its purpose presses upon us with urgency.
Let this anniversary mark not hesitation, but resolve. Let it be remembered not as a pause, but as a renewal. Japan calls upon all States Signatories to stand shoulder to shoulder, to fortify the verification regime, and to uphold without wavering the global norm against nuclear testing.
Thank you.
At the outset, Japan offers its heartfelt gratitude to the Chair of Working Group B, to the task leaders, to the chairs of the expert meetings, and to the Provisional Technical Secretariat, whose steady labor has prepared the ground upon which we now stand.
Thirty years have passed since the CTBT was opened for signature. This solemn milestone meets us in the same year as the NPT Review Conference. Yet we gather in unsettled times. Trust among nations is strained; strategic dangers grow sharper and less predictable. In such an hour, the CTBT is no distant ideal. It is a living shield. For Japan, it remains a practical and steadfast pillar of the global regime for disarmament and non-proliferation.
That pillar stands firm because of its verification regime—above all, the International Monitoring System and the International Data Centre. These are not mere instruments of science. They are the means by which the will of the international community is made visible, by which solemn promises are tested and proven in fact.
Even before entry into force, our duty is clear. Verification must grow stronger as risks grow greater. Within the Preparatory Commission, we must deepen our capacity for detection, refine our collection of data, and sharpen our analysis. The knowledge assembled in this Working Group, joined with the advancing technologies of our age, must be brought fully to bear.
Yet machines and methods alone will not suffice. States Signatories must actively use their National Data Centres to judge whether events constitute nuclear tests. Relevant data should be shared swiftly and transparently. Where provision of data remains lacking, it must be improved in earnest. Such openness is not a courtesy; it is the lifeblood of the Treaty’s credibility and the safeguard of its very purpose.
We do not ignore the strain of financial pressures. To sustain the International Monitoring System—the very heart of verification—grows ever more demanding. Its maintenance is not only an urgent task requiring immediate attention, but also a responsibility that demands a medium- to long-term vision to ensure its enduring resilience and effectiveness. But it is in times of constraint that commitment is most truly measured. Japan calls upon all States Signatories to pursue practical solutions and to secure the sustainability of the IMS.
Capacity building, too, is essential. Since 1995, Japan has conducted the Global Seismological Observation Training Course through JICA with the support of Building Research Institute. This year, eight trainees joined, bringing the number of participants to more than 300 from some 80 countries. By strengthening the analytical and operational power of National Data Centres, we reinforce the Treaty’s global detection network and deepen the confidence we share.
Regarding On-Site Inspection, Japan welcomes the forthcoming Integrated Field Exercise 2026 and expresses its appreciation to the Government of Namibia for hosting it.
Mr. Chair,
On North Korea, Japan recalls with deep concern that within the three decades since the CTBT’s opening for signature, North Korea has conducted six nuclear tests and is a core mandate issue of the CTBT and hence should continue to be taken up during the Prep Com and Working Groups. North Korea’s nuclear issue is not merely a regional concern but a global challenge that strikes at the very core of the CTBT’s purpose and verification mandate.
Japan expresses serious concerns over the advancement of North Korea’s nuclear and missile development. We urge North Korea not to conduct any destabilizing or provocative actions, including a nuclear test. Japan also urges North Korea to comply with its obligations under the relevant UN Security Council resolutions, to return to full compliance with the NPT and to sign and ratify the CTBT at the earliest possible date. Japan reiterates its firm dedication to achieving the complete denuclearization of North Korea in accordance with UNSC resolutions and remains resolute in upholding its crucial responsibilities toward this goal.
Mr. Chair,
Thirty years on, the CTBT is unfinished work—yet it is no empty vow. Its verification regime functions. Its norm endures. Its purpose presses upon us with urgency.
Let this anniversary mark not hesitation, but resolve. Let it be remembered not as a pause, but as a renewal. Japan calls upon all States Signatories to stand shoulder to shoulder, to fortify the verification regime, and to uphold without wavering the global norm against nuclear testing.
Thank you.