On this day, the citizens of Hiroshima gather in the shadow of this historic UNESCO World Heritage site to commemorate those who perished in the nuclear attack of 6 August 1945.

People around the world see this solemn ceremony not just as an occasion to honour the hibakusha and to pay respects to the dead; they see it as a powerful reminder of the work ahead in achieving a world free of nuclear weapons.

Nuclear proliferation is one of the most pressing problems confronting our world. Tens of thousands of nuclear weapons remain, many of them on “hair-trigger” alert.  The emergence of a nuclear black market and attempts by terrorists to acquire nuclear weapons and materials have compounded the nuclear threat.

Today, our challenge — as it was for the founders of the United Nations — is to make the world safer for succeeding generations. This requires us to continue to work towards a world free of nuclear dangers, and ultimately, of nuclear weapons.

Allow me to pay special tribute to Mayor Tadatoshi Akiba of Hiroshima and Mayor Tomihisa Taue of Nagasaki, who together with their predecessors have advanced the “Mayors for Peace” initiative for the past 25 years. This partnership now has the support of more than 1,600 mayors from 120 countries around the world. It has not only helped inform millions of people around the world of the catastrophic effects of the nuclear attacks in 1945; it has also drawn attention to the dangers that cities would face with any future use of such weapons, and reminded all city-dwellers of their collective stake in disarmament.

Much of the burden of achieving our goal will be borne by young people. I am sure they will continue to be inspired by the memory of Sadako Sasaki, who was two years old when the bomb was dropped on Hiroshima, and died of the “atom bomb disease” 10 years later. Sadako lives on in the image of the thousands of origami peace cranes she made. She lives on in the words inscribed under her statue here in the Hiroshima Peace Park: “This is our cry. This is our prayer.  Peace in the world.”

This is also my prayer. I am honoured to pay my respects on this solemn occasion, and I hope the year ahead will bring us a few steps closer to a safer and more peaceful world for all. We must do all we can to turn back the tide of nuclear proliferation, and ensure that Sadako’s experience is never repeated.  I know the people of Hiroshima and Nagasaki will continue to play their part in this vital cause for all humankind.