SIRTE, Libya, July 1 (Xinhua) -- The African Union (AU) started its 13th summit in Sirte, Libya on Wednesday, with UN, Arab, African leaders calling for collective and resolute actions to face challenges on agricultural investment and regional peace and security.

　 AGRICULTURAL INVESTMENT, FOOD SECURITY

　 The three-day summit in Sirte, 500 km southeast of the Libyan capital of Tripoli, is dedicated to "investing in agriculture for economic growth and food security" in the world's poorest continent.

　 Addressing the opening ceremony of the summit, Deputy Secretary-General of the United Nations Asha-Rose Migiro said more than half of all Africans currently live in extreme poverty, calling on African leaders to "use this summit to mobilize action to protect the poor...