The UN is holding a major conference to highlight the Iraqi refugee crisis, which it says has been largely ignored by the international community.
The UN refugee agency estimates 50,000 people are fleeing the violence in Iraq each month and that up to four million Iraqis are now living away from home.
Most refugees go to neighbouring Syria and Jordan, which have together accepted about two million refugees.
Officials from more than 60 countries are attending the meeting in Geneva.
The UNHCR says many of the refugees live in acute poverty with little access to health and education.
Antonio Guterres, the head of the UN refugee agency, says the international community has focussed on the turmoil inside Iraq but neglected this dimension of the humanitarian crisis.
"There is not enough attention on the fact that four million people have been displaced and they live in very, very difficult circumstances, some of them, both inside Iraq and outside Iraq.
"And the expression of international solidarity is absolutely crucial because, until now, let's be honest, they have been basically abandoned by us all," Mr Guterres said.
The UN wants commitments from wealthy countries, above all the US and EU, to support Jordan and Syria and to accept some of the most vulnerable refugees themselves.
Within Iraq another 1.9 million people are internally displaced, many of them sheltering with friends or relatives who have little space or food to share.
The agency says the refugee crisis in Iraq is the biggest population exodus since the displacement of the Palestinians following the creation of Israel in 1948.
BBC