Claim by US officials follows declaration of three new famine zones by UN and warning that more areas are vulnerable. US officials say that the famine in Somalia has killed more than 29,000 children in the last 90 days.
Separately, the UN has declared that three new regions in Somalia are famine zones, making a total of five regions affected by famine thus far in the Horn of Africa country. The UN had said last month two regions were suffering from famine.
The Food and Agriculture Organisation (FAO), the UN's food arm, has said that famine is likely to spread across all regions of Somalia's south in the next four to six weeks.
Famine, as defined by the UN, refers to situations when at least 20 per cent of households face food shortages so severe that they are unable to cope with it and more than two people out of 10 000 people die daily. Additionally, famine conditions are likely to persist until December, FAO said. Across Somalia, 3.7 million people are in crisis out of a population of 7.5 million, the UN says.