Raising to 90 percent the global breastfeeding rate for infants to six months would save an estimated 13 percent of the 10 million under-age-5 deaths a year, Vallenas said.

In a statement released to mark World Breastfeeding Week, August 1-7, WHO Director-General Margaret Chan said it was also important that mothers in disaster zones be given the support they need to continue or restart breastfeeding.

"During emergencies, unsolicited or uncontrolled donations of breast milk substitutes may undermine breastfeeding and should be avoided," Chan said, arguing abandoning breastfeeding could put vulnerable child lives at extra risk. "The focus should be on active protection and support of breastfeeding."