UN Secretary-General Ban Ki-moon Friday called on the international community to "seize the opportunity and build a world that is fit for children" at a time when children across the globe fall victim to preventable diseases, such as malnutrition, violence and exploitation.

UN Secretary-General Ban Ki-moon addresses the ceremony marking the Universal Children's Day and the 20th anniversary of the Convention on the Rights of the Child at the UN headquarters in New York Nov. 20, 2009. Ban Ki- moon Friday called on the international community to "seize the opportunity and build a world that is fit for children" at a time when children across the globe fall victim to preventable diseases, such as malnutrition, violence and exploitation. [Shen Hong/Xinhua]

Delivering opening remarks at the occasion to mark the Universal Children's Day and the 20th anniversary of the Convention on the Rights of the Child, the secretary-general said, "Over the past 20 years, the convention has been our beacon, our template, our guide in protecting and nurturing the youngest and most vulnerable members of society."

"It has become history's most widely accepted international human rights treaty," Ban said at the event at the UN headquarters in New York, supported by the UN Children's Fund (UNICEF).

But in realizing the rights of the convention, he said that it still "remains a huge challenge," where millions of children succumb to largely preventable causes before their fifth birthday.

"Millions of children still die before their fifth birthday from largely preventable causes," the secretary-general said. " Millions more lack access to clean food, water and education, and are victims of violence and exploitation."

"Children are physically and emotionally vulnerable," he said. "They are often the first to succumb to disease and malnutrition. They can be scarred for life by mental or emotional abuse."

"That is why children should always have the first claim on our attention and resources," Ban said. "But this is especially true now, at a time when multiple crises threaten the poorest people, particularly in developing countries."

"Children must be at the heart of our thinking on climate change, on the food crisis, and on the other challenges we are addressing on a daily basis," Ban said.

"Even during the most severe economic crisis in decades, the means are at hand," he said.

Half a century has passed since the UN General Assembly adopted a Declaration of the Rights of the Child to initiate actions aimed at benefiting and promoting the welfare of children worldwide. Twenty years have passed, too, since the same assembly got a Convention on the Rights of the Child signed to clearly establish the civil, political, economic, social and cultural rights of children.

Now, 193 United Nations member states have ratified that convention, making it one of, if not the most endorsed conventions in the world.

Actions are needed in order to follow up on the ratifications to change, improve and secure the treatment and welfare of children in the world.