The UN is set to hold an emergency session to boost international aid to flood-hit Pakistan.

联合国将举行一场紧急会议以增加对巴基斯坦的国际援助。

Millions of people are without even basic supplies

It says it has raised nearly half of the $460m (£295m) needed for initial flood relief efforts（救灾工作） but that the response remains¹ slow.

The number of people in need of immediate² assistance in Pakistan has now risen to eight million.

The rise comes amid fears of new flooding, as water continues to surge（激增，汹涌） south along the Indus River.

The UN's Secretary General Ban Ki-moon called the special session after visiting Pakistan last week to assess the disaster.

He described the situation as "heart-wrenching" and said he had never seen a disaster on such a scale.

The member states are expected to adopt a resolution urging the international community "to extend full support and assistance" to Pakistan in its efforts "to mitigate³（减轻，缓和） the adverse⁴ impacts（负面影响） of the floods and to meet the medium- and long-term rehabilitation⁵（复原） and reconstruction⁶ needs".

The BBC's Kim Ghattas at the UN says the resolution will not produce any concrete action plan but is a sign of how nervous the US and the UN are about the level of international assistance given to Pakistan so far.

US Secretary of State Hillary Clinton is expected to announce an increase in US donations, said White House officials.

The session is a clear attempt to build a sense of urgency about a natural disaster that will have a lasting⁷ impact on a country that is key to the fight against the Taliban and al-Qaeda, says our correspondent.

'Pretty scary'

A UN spokesman said on Wednesday that there had been an improvement in the speed of donations from the international community, after a sluggish⁸（萧条的，迟钝的） response in the first days of the appeal.

"Donors⁹ are realizing the scale of the disaster," Maurizio Giuliano told Reuters, "but the challenges are absolutely massive and the floods are not over."

"The size of this disaster is equivalent to Austria, Switzerland and Belgium combined. That's pretty scary."

On Wednesday, the European Union promised an extra $39m following higher commitments from Australia and Japan, while the Islamic Development Bank pledged $11.2m.