"Thousands and possibly millions of Sudanese children suffer from exploitation and discrimination," said Ted Chaiban, UNICEF’s representative in Sudan, at the launch of the "State of the World's Children 2006" report.
"The report ... comes at an important time when attention is being focused on the practice of female genital mutilation/cutting in Sudan," he added.
Calling on governments, religious leaders, health practitioners and parents to put an end to the practice, UNICEF said about 75 percent of Sudanese girls are circumcised before the age of 14.
The ritual is carried out ostensibly to ensure the girl's chastity, health, beauty and family honour.
Samira Ahmed, a UNICEF child protection officer, said there was no legal framework for banning the ritual.
The report indicated that in northern Sudan, children from middle - and upper-class families are twice as likely to be vaccinated against killer childhood diseases than poor children.
"Government at local, state and federal levels, UNICEF, WHO [World Health Organization] and other agencies are working to ensure that immunisation services reach all children," Chaiban said.
UNICEF, he added, planned to emphasise the importance of immunisation against measles, which kills as many as 30,000 Sudanese children a year.
Vaccination efforts for measles in Darfur managed to prevent a major outbreak of the deadly disease, Chaiban said. In southern Sudan, nearly 4.5 million children will be vaccinated within the next 18 months.
"Efforts are being made to ensure children have access to services and are covered by a protective framework. Thousands of nomadic children, who for generations were largely hidden from the public education system, are now attending school," Chaiban noted.
With regard to the ongoing conflict in the western Sudanese region of Darfur, which affects over 3 million children, the report observed: "Discrimination on the basis of ethnicity can erode self-worth and confidence in children and deprive them of opportunities for growth and development, blunting the promise that is every child's birthright."
"Reaching the unreached, excluded children - from El Geneina to Torit to Kassala - is an imperative," Chaiban said. "They deserve to be seen. They deserve to have their rights fulfilled."
The global report warned that 8.7 million children under the age of five will die before 2015 if the Millennium Development Goals (MDGs) are not met.
If the MDGs were met, UNICEF noted, the lives of 3.8 million children would be saved.
The annual UNICEF report aims to provide updated statistics regarding the "excluded and invisible" children in 189 countries, including Sudan, that adopted the MDGs as part of the Millennium Declaration in 2000.
The MDGs include eradicating extreme hunger and poverty, ensuring that all boys and girls complete primary school, reducing child mortality rates among children under five, ensuring environmental stability and reducing maternal mortality rates by three-quarters.