Childhood death rates around the world have halved since 1990 but an estimated 6.6 million children under the age of 5 still died last year, the U.N. children's agency said Friday.  

Nearly half of all children who die are in five countries: Nigeria, Congo, India, Pakistan and China, it said in a report.   "Progress can and must be made," said Anthony Lake, UNICEF's executive director.

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A two-year-old girl recovering from malaria and malnutrition in Mauritania last year. (Susana Vera/Reuters)

 "When concerted action, sound strategies, adequate resources and strong political will are harnessed in support of child and maternal survival, dramatic reductions in child mortality aren't just feasible, they are morally imperative."  

The top killers are malaria, pneumonia and diarrhea, the report said, taking the lives of about 6,000 children under age 5 daily. A lack of nutrition contributes to almost half of these deaths, the U.N. said.  

Eastern and Southern Africa have reduced their death rates for children under 5 by more than 50 per cent since 1990. West and Central Africa are the only regions not to have at least halved the number of children under 5 dying over the past 22 years, the U.N. said.  

Nigeria bears more than 30 per cent of early childhood deaths for malaria and 20 per cent of the deaths associated with HIV. Globally, the country accounts for one in every eight child deaths, the U.N. said.    

While these numbers are grim, the rate of improvement globally seems to have plateaued at about 4 per cent improvement per year since 2005, the report said. The estimated numbers are based on solid data from about half the world's countries.

And for regions with the biggest problems, they had to rely on modeling techniques.  

Countries like Bangladesh, Ethiopia and Brazil showed tremendous progress, due in part to increased community health care. Affordable and increased interventions — like treated mosquito nets, medicines, rehydration treatments and improved access to safe water — helped improve the early childhood death rate in other countries as well.   

But improvements were not as bold in countries like Nigeria, Congo, Sierra Leone and Pakistan, the report showed.  

Lake said a new sense of urgency was needed to improve the figures.  

 "Yes, we should celebrate the progress," he said. "But how can we celebrate when there is so much more to do?"