The crisis, driven by prolonged drought, destructive floods and rising global fuel prices, has left millions vulnerable to hunger, displacement and disease across the Horn of Africa nation.
By Yunis DekowSudan and South Sudan are the hardest hit. Sudan has the highest number of people affected at 24.6 million, with famine and famine risks confirmed in several regions.
By Maureen KinyanjuiThe Integrated Food Security Phase Classification (IPC), which is used by governments and international bodies to identify hunger levels around the world, has raised its classification to Phase 5 - the highest and most severe.
By Rose AchiengThe aid comes as violence surges in parts of South Sudan following renewed tensions between President Salva Kiir and Vice President Riek Machar, which escalated into open conflict in March.
By Maureen Kinyanjui