This is the moral challenge of our generation. Not only are the eyes of the world upon us. More important, succeeding generations depend on us. We cannot rob our children of their future.

Universal ratification of the Optional Protocol on the Involvement of Children in Armed Conflict will establish an international moral consensus that no child should take part in hostilities or be involuntarily recruited and that former child soldiers should be assisted by their governments after a life of violence and distress.

The international community cannot accept that whole communities are marginalized because of the color of their skin. People of African descent are among those most affected by racism. Too often, they face denial of basic rights such as access to quality health services and education. Such fundamental wrongs have a long and terrible history.

I call for the need of world leaders to address climate change and reduce the increasing risk of disasters- and world leaders must include mayors, townships and community leaders.

You are here to step into the shoes of UN ambassadors - to draft resolutions, to plot strategy, to negotiate with your allies as well as your adversaries. Your goal may be to resolve a conflict, to cope with a natural disaster or to bring nations together on an issue like climate change. You may be playing a role, but you are also preparing for life. You are acting as global citizens.

On this International Day, let us promise to make peace not just a priority, but a passion. Let us pledge to do more, wherever we are in whatever way we can, to make every day a day of peace.

Since [violence against women] is rooted in discrimination, impunity and complacency, we need to change attitudes and behavior - and we need to change laws and make sure they are enforced just like you are doing in Cuba.