GENEVA, June 2 (Reuters) - Surging global transport costs and supply chain disruptions linked to the Middle East crisis are threatening the delivery of lifesaving aid to children, the U.N. children's agency warned on Tuesday. Nearly 100 days after the outbreak of the Iran war, heightened insecurity around key Gulf shipping routes has driven up fuel prices and insurance premiums, while congestion at alternative ports has compounded disruptions, hampering aid deliveries. • U.N. children's agency UNICEF said it was increasingly relying on air freight due to shipping delays.