More than half the world’s countries are falling behind in a U.N. campaign to reduce child deaths by two thirds by 2015, the U.N. children’s agency UNICEF reported on Thursday.

Worldwide in 2002, the latest year for which reliable data is available, 1 in 12 children died before age 5, representing some 11 million preventable deaths each year.

At the current rate of progress, the child mortality rate will have fallen by just 23 percent by 2015, well short of the 66 percent goal set at a U.N. Millennium Summit in New York four years ago, it said.

World leaders at that summit agreed to bring down the global child mortality rate to 31 per 1,000 from the 1990 rate of 93 per 1,000.

In all, 98 countries are either stagnating or going backwards in their quest to meet the U.N. goal, while 90 countries, including 53 developing nations, are on track to fulfill the goal, UNICEF said.

While most of the countries with the worst death rates are in sub-Saharan Africa, war-torn Afghanistan in central Asia also figures near the bottom of the rankings, with 257 deaths by age 5 out of every 1,000 live births, UNICEF said.

In four countries - Sierra Leone, Niger, Angola and Afghanistan - more than one of every four live births ends in death before the child’s fifth birthday, it said.

In another six - Liberia, Somalia, Mali, Guinea Bissau. Burkina Faso and the Democratic Republic of Congo - more than one of every five live births ends in death by age 5.

Wealthy industrial nations, by contrast, average seven child deaths per 1,000 live births.

The country losing the most ground on child mortality since 1990 is Iraq, which lost two wars and was under tough U.N. sanctions during that period, UNICEF said.

Iraq is one of a number of countries, most of them in subSaharan Africa or Eastern Europe, where child mortality has increased rather than fallen since 1990, UNICEF said.

Malta has shown the most progress in bringing down its infant mortality rate, followed by Malaysia, Egypt, Portugal and Oman, the U.N. agency said.

“The world has the tools to improve child survival, if only it would use them,” UNICEF head Carol Bellamy said.

“No government should be allowed to let another 10 years pass with so little progress for children. Leaders have agreed to goals and they must be held accountable,” she said.

Most preventable infant deaths occur because of inadequate health care for mothers and a lack of skilled help during childbirth, UNICEF said.

Infectious and parasitic diseases including diarrhea, severe respiratory ailments, malaria and measles are the next biggest killers, it said, adding that malnutrition, unsafe water, bad sanitation, AIDS, armed conflicts and social instability were also significant contributing factors.

“Vaccines, micronutrient supplements and insecticide-treated mosquito nets don’t cost much, and would save millions of children. But not enough children are being reached with these basic life-savers,” Bellamy said.