Pakistan is struggling to deal with its worst natural disaster in history. More than 1,500 people are dead and millions homeless in floods that have devastated parts of the country.

The flooding was triggered by torrential rain nearly a month ago and has affected more than 10 per cent of the population. Many, including children, are at risk of disease and starvation and their misery is being compounded by the slow pace of international aid.

In one month after the disaster, the United Nations has raised only about 70 per cent of its $460mn emergency appeal for Pakistan.

On Wednesday's Riz Khan we ask: Is the issue of "donor fatigue" or negative perceptions about Pakistan to blame for sluggish international aid for flood victims in that country?

Joining the show will be Sir John Holmes, the outgoing United Nations under-secretary-general for humanitarian affairs; Mosharraf Zaidi, a Pakistani journalist and blogger; and Kalsoom Lakhani, who is leading efforts by young Pakistanis in the US to mobilise aid for flood survivors.

You can join the conversation. Call in with your questions and comments on Wednesday, August 25, at our live time of 1630GMT. Repeats air at 2130GMT, and the next day at 0230GMT and 1130GMT.