US Secretary of State Hillary Clinton has urged all 70 nations attending a conference on Afghanistan's future to help the country succeed. She told delegates at the one-day event in The Hague that the international effort there had been "undermanned and underfunded" over recent years. Among the countries to offer help has been US foe Iran. The conference comes after the US announced a major policy rethink on its approach towards Afghanistan. The meeting, called by the UN, comes amid widespread concern that not enough progress has been made since the US-led invasion in 2001. Support for Afghan reconstruction is being sought beyond the mainly-Western countries which have troops there.