By Susannah Price
BBC correspondent at the United Nations
A UN report has found that the world is more unequal today than it was 10 years ago, despite considerable economic growth in many regions.
Growth has not eased the burden on the poor, says the report
This year's report on the world's social situation argues that although living standards have improved in some places, poverty remains entrenched.
The authors warned that focusing only on economic growth is an ineffective way of achieving development.
They said wealthy nations are the main beneficiaries of economic development.
The UN report - drawn up by the UN's Economic and Social Affairs Department - found that the gap between rich and poor is now wider than it was a decade ago, and called for immediate action.
The report focuses on worldwide inequality in income and wealth, along with other areas such as health and education.
The report said that although China and India had seen considerable income growth, there was a wide income gap.
It said it would be impossible for the 2.8bn people living on less than $2 a day to ever match the consumption levels of the rich.
The UN secretary general said the report showed the development agenda could not be advanced without addressing inequality, such as the gap between skilled and unskilled workers and between the formal and informal sectors.
The report recommends expanding opportunities for productive employment, bringing marginalized groups into society and working to distribute the benefits of what it called the increasingly open world economy.