(CNN) "Whatever may be the nature of the uncertainties and the tensions in which the world is placed today, and whatever may be their causes, there should be no problem that cannot be resolved peacefully with the united strength of 80 nations which now constitute our organization."

In the 70 years since the United Nations was founded, it has helped the international community overcome Cold War tensions to resolve many regional conflicts. Today, in developed and developing countries alike, the greater movement of people, freedom in trade and investment, and advances in information technology have enriched many people's lives.

Japan, for its part, has continued to serve as a steadfast pillar of the United Nations during its six decades of membership. We are, for example, the second-largest financial contributor to the United Nations , and have provided more than $330 billion of Official Development Assistance accepted 560,000 trainees from developing nations and dispatched 190,000 experts and volunteers . Asian nations' role as the growth center of the global economy is ample testimony to the impact these contribution have made. In addition, Japanese personnel have participated in peacekeeping operations in countries such as Cambodia and Timor-Leste and provided long years of on-the-ground support for nation-building programs.

But the world has changed drastically since the United Nations was established, and the evolution toward a borderless world is continuing, posing new challenges to mankind. It is therefore essential that the role of the United Nations evolves to meet those challenges. The international community must stand ever more united, not divided, to find solutions to these increasing challenges. And the key to doing so is to break down an outdated "silo approach" to international affairs.

The reality is that the issues we face are no longer one country's problem, and they can no longer be confined to a single policy area. Tackling the prolonged refugee crisis, for example, which involves multiple regions and states, as well as complex political dynamics, requires a solution that gets to the root causes of a given issue. That means doing more than just saving refugees from the immediate crisis they find themselves in. Instead, we also need to empower them through education and vocational training so that they are ready to rebuild their lives if they choose to return home. This makes bridging the gap between humanitarian efforts and development assistance even more important.

But tackling such challenges requires strong leadership from the United Nations. The organization must live up to its full potential even as it faces finite resources in trying to do so. That will require making the United Nations a more unified organization -- "One UN" -- where UN bodies coordinate more closely. This process is unavoidable, even though it might require bold and painful organizational reforms. One of the most urgent of those is reform of the UN Security Council.

With a growing range of pressing issues to address, including the situation in Syria, as well as North Korea's missile launches and recent nuclear tests in defiance of UN resolutions, the role of the Security Council continues to grow in importance. In particular, North Korea has enhanced its capabilities this year by conducting two nuclear tests and launching at least 20 ballistic missiles. Clearly, North Korea's nuclear and missile threat has entered a new stage. Meanwhile, North Korea's human rights violations, including the issue of the abductions of Japanese and other citizens, could undermine regional stability and thus should be seen as inseparable from matters of international peace and security. All this is a reminder that reform simply cannot wait, since the Security Council takes primary responsibility for the maintenance of international peace and security.

Since the United Nations' inception, the international community has undergone tectonic changes. The number of member states has grown from 51 to 193 countries as Asian and African countries won their independence, gaining greater prominence on the international stage -- both politically and economically -- in the process.

Yet despite these changes, the composition of the Security Council, which has important responsibilities in terms of global peace and security, remains almost entirely unchanged. This means that the entire continent of Africa, which is the focus of many of the Security Council's agenda items, does not have any permanent representation. With that in mind, three weeks ago, at the Sixth Tokyo International Conference on African Development I co-hosted in Nairobi, I expressed my firm support for the goal of having permanent African representation on the Security Council by 2023, while sharing their vision of correcting "historical injustice" and respecting their own initiative, "Agenda 2063."

Clearly, a priority for the United Nations should be to address the composition of the Security Council to help increase its representativeness, legitimacy and effectiveness. There is a general consensus within the international community of the need for Security Council reform, and I see support for reforms as a litmus test of the seriousness of a nation's desire for global peace and security.

Looking ahead, developed and developing countries alike face common challenges: building economic structures that drive growth, countering global warming while reducing dependence on fossil fuels and tackling pollution. Other shared goals include developing high quality and sustainable infrastructure, meeting the challenge of aging societies, and creating more robust health and education systems.

In a few short decades, Japan has successfully managed to overcome many of these issues. We are now also pioneering efforts to promote proactive engagement of our aging population, and to also create a society in which all women can shine. That is why I believe Japan can make a unique contribution to the international community, including through becoming a permanent member of the Security Council.

Japan has long drawn on its unique strengths to contribute to global peace and stability. As the only country to have experienced atomic bombings, we vigorously support nuclear disarmament and nonproliferation efforts, submitting resolutions at the United Nations every year calling for the eradication of nuclear weapons. Based on our track record of bringing a global perspective to resolving issues in Africa and the Middle East, among other regions, and our commitment to making a proactive contribution to peace, I firmly believe that as a permanent member of the Security Council, Japan would provide a major impetus toward global peace and security.

Just two months after Foreign Minister Shigemitsu delivered his country's first speech to the United Nations, Nobusuke Kishi became Prime Minister. In a speech just before taking office, Kishi said: "Japan must always stand ready to make as much contributions as would be necessary to strengthen the authority of the United Nations and to attain world peace through the UN."

On the 60th anniversary of Japan's UN membership, I reaffirm this commitment -- and our desire to fulfill our role as a responsible member of the international community, one that will continue to be proactive in working toward a United Nations that is effective and capable of keep pace with these fast-changing times.