L'AQUILA, Italy — President Barack Obama this morning hailed "candid and spirited discussions" at the G-8 summit, saying the world must come to grips with chronic problems like economic stagnation and climate change.

Summing up three days of talks with fellow leaders in Italy, Obama said he and others have agreed a full recovery from the global economic recession is "still a ways off." He also noted he and the leaders of other industrialized nations had productive discussions about limiting the proliferation of nuclear weapon systems.

Obama said many difficult challenges still confront the world's leaders, saying "we can either shape our future or let events shape it for us."