In his first speech to the United Nations' General Assembly, Mr Miliband said the world could not stand united against shared threats when it was so divided by economic and political disparities.

He urged the UN to lead its member states towards equality to promote stability and prosperity across the world.

"The mission is, for my government, driven by both moral purpose and national interest," he said.

"We must address the insecurity and inequality that exists beyond our borders if we are to enhance security and prosperity within our borders.

"We live in a more prosperous world, a more peaceful world, a more democratic world than ever before. Let's commit to living in a more equal world."

He went on: "The need for governments and international institutions to reduce inequalities, and promote our common humanity, is stark.

"National action is not enough. Because the causes of inequality cross national boundaries, we need co-operation between nations, bilateral and multilateral, led by the UN."

He said progress on aid needed to be combined with a new global trade deal which opens up economies on a fair basis and added that the UK believes the conclusion of the Doha trade talks this year is "not just necessary but possible and we will walk towards that goal".

In addressing major issues around the world, Mr Miliband called on the military regime in Burma to "allow peaceful protest, encourage national dialogue and promote genuine reconciliation".