Africa has one of highest death rates for children under five
Death rates for children under five have halved in some regions since 1990, but about 6.6 million still are thought to have died last year, according to a new report on Friday.
The UN Children's agency says the highest death rates are in Africa and Asia and nearly half of all children who die are in five countries: Nigeria, Congo, India, Pakistan and China. In West and Central Africa, there has been virtually no change in the number of children who die every year since 1990.
The UN says the top killers are pneumonia, diarrhea and malaria.
Solid numbers were only available from about half of the world's countries and experts used modeling techniques to estimate the number of deaths worldwide.
Around 6.6 million children perished before their fifth birthday last year, compared to 12.6 million in 1990, said the report by UNICEF, the World Bank and the World Health Organisation.
The report credited more effective and affordable treatments, new ways of delivering healthcare to the poor, as well as political commitment for the gains.
But it also underscored that much remained to be done.
"This trend is a positive one. Millions of lives have been saved," said Anthony Lake, UNICEF's executive director.
However, "most of these deaths can be prevented, using simple steps that many countries have already put in place. What we need is a greater sense of urgency."
All regions except Oceania and sub-Saharan Africa saw more than a 50% decline.
In eastern Asia, early childhood deaths have dropped by 74% and in Northern Africa the decline was 69%.
But child mortality rates were still elevated in some regions, with around 80% of under-five deaths in 2012 still taking place in sub-Saharan Africa and South Asia.
Currently some 18 000 children under five die every day. Half of those deaths take place in five countries: China, the Democratic Republic of the Congo, India, Nigeria, and Pakistan.
The immediate causes are mostly pneumonia, prematurity, birth asphyxia, diarrhea and malaria, according to the report.
But 45% can be linked to undernutrition, it said.
The report also said that, despite the improvements, the effort to cut childhood mortality was falling short of the target set in the Millennium Development Goals – bringing the rate down by two-thirds between 1990 and 2015.