Media playback is unsupported on your device Media caption Aleem Maqbool reports from a school in Pakistan's Sindh province where there are children but no teachers

It will be more than 70 years before all children have access to primary school, says a report from the United Nations Educational, Scientific and Cultural Organisation (Unesco).

World leaders had pledged that this would be achieved by 2015.

The report says 57 million remain without schools and at the current rate it will be 2086 before access is reached for poor, rural African girls.

Report author Pauline Rose describes these as "shocking figures".

The lack of education for all and the poor quality of many schools in poorer countries is described as a "global learning crisis".

In poor countries, one in four young people is unable to read a single sentence.

Greatest need

The study from Unesco, published on Wednesday in Addis Ababa in Ethiopia, is an annual monitoring report on the millennium pledges for education made by the international community.

But it warns that promises such as providing a primary school place for all children and increasing the adult literacy rate by 50% are increasingly unlikely be kept.

MOST CHILDREN OUT OF SCHOOL Nigeria

Pakistan

Ethiopia

India

Philippines

Burkina Faso

Kenya

Niger

Yemen

Mali Source: Unesco

It also warns that aid for education is declining rather than increasing and is not being targeted at the poorest countries with the greatest need.

It reveals that the single biggest recipient of aid for education is China - which receives aid worth a value 77 times greater than Chad.

The report, based on the latest data which is from 2011, shows that there are still 57 million children who do not even get the first basics of schooling.

More optimistically, this represents an almost 50% drop in out-of-school children since 2000.

The report shows that if the early momentum had been sustained the goal could have been achieved. But since 2008, progress has "all but ground to a halt".

Conflict zones

Countries such as India, Vietnam, Ethiopia and Tanzania have made considerable progress in expanding the reach of education.

There are also improvements in quality, with Vietnam now among the most impressive performers in the OECD's Pisa tests, overtaking the United States.

Image copyright Reuters Image caption Hanoi in the rain: Vietnam's school system has grown in size and quality

The greatest problems are in sub-Saharan Africa, with particular weaknesses in parts of west Africa.

Nigeria has the single greatest number of children without a primary school place - a higher figure now than when the pledges were made at the beginning of the century.

About half of the lack of access to school is the result of violence and conflict.

But Afghanistan, which has faced 35 years of conflict, is managing to reopen schools and the country's education minister told the BBC that a grassroots campaign will see all children having primary school places by 2020.

Gender gap

The report, produced by the Paris-based educational arm of the United Nations, highlights the inequalities in access to places.

Image copyright Tagaza Djibo/ Unesco Image caption Girls in a rural school in Niger keep quiet while another class is taught

Girls are more likely to miss out on school than boys and this is accentuated more among disadvantaged, rural families.

As such, poor, rural girls are forecast to be the slowest to have school places, with Unesco projecting it will take until 2086.

It means that the five-year-olds who are now missing out on beginning school will be grandmothers before universal primary education is achieved.

It will not be until the next century, 2111, before poor rural girls will all have places in secondary school, at the current levels of progress.

LEAST LEARNING IN SCHOOL Niger

Mauritania

Madagascar

Chad

Benin

Mali

Cote d'Ivoire

Burkina Faso

Congo

Senegal Source: Unesco

Within countries there are big differences in access to schools.

And the ability to provide places for better-off children and for boys shows what should also be achievable for girls and the poor, says Dr Rose.

"It shows the importance of focusing on the marginalised," says Dr Rose, director of the global monitoring report team.

The study also raises concerns about the quality of education in many poorer countries.

There are 130 million children who remain illiterate and innumerate despite having been in school.

It means that a quarter of young people in poorer countries are illiterate, which has far-reaching implications for economic prospects and political stability.

Wasted spending

The report estimates that in some countries the equivalent of half the education spending is wasted because of low standards, which it calculates as a global loss of $129bn (£78bn) per year.

There are practical barriers to learning. In Tanzania, only 3.5% of children have textbooks and there are overcrowded class sizes of up to 130 pupils in Malawi.

Image copyright Tagaza Djibo/ Unesco Image caption Gounaka village, Niger: Many leave primary school before learning the basics

The study calls for more support in raising the quality of teaching. In west Africa, it warns of too many teachers who are on low pay, temporary contracts and with little training.

The quantity of teachers would also need to be increased, with an extra 1.6 million needed to provide enough primary school places.

The report says to reach the goal of universal primary education would require an extra $26bn (£16bn) per year.

But aid to education has declined at a greater rate than overall aid budgets, says the report.

"One of the things that we found shocking was that low income countries faced the biggest losses in aid," says report author, Dr Rose.

The biggest recipient, China, gains from support for scholarships, mostly from Germany and Japan.

Moves are already underway for setting post-2015 targets.

The report says that the next goals must include an awareness of the quality of education and teaching.

"We must also make sure that there is an explicit commitment to equity in new global education goals set after 2015, with indicators tracking the progress of the marginalised so that no-one is left behind," said Unesco director-general Irina Bokova.