About four in every 10 children in the Pacific are not enrolled in pre-school education, a report by the UN children's agency UNICEF has revealed.

The report, A World Ready to Learn: Prioritising quality early childhood education, shows that children enrolled in at least one year of pre-primary education are more likely to develop the critical skills needed to succeed in school.

UNICEF's Pacific representative, Sheldon Yett, said this put Pacific children at a disadvantage.

Pacific governments should invest more in pre-school education to ensure learning foundations are there, Mr Yett said.

More than 175 million children - about half of pre-schoolers globally - are not enrolled in pre-primary education, he said.