U.S. President Barack Obama, mixing with other world leaders at the the United Nations on Thursday over lunch, toasted the organization and urged his dining companions to work harder for peace.

“In the months and years ahead, the challenges we face will require the work of all nations and all peoples … it will require the leadership of everybody in this room,” he said.

Obama arrived late for the lunch after a bilateral meeting with Chinese premier Wen Jiabao, waving and greeting other leaders as they tucked into pate on toast and sipped chilled white Burgundy wine.

Zimbabwe’s Robert Mugabe glanced over his shoulder as Obama walked past his table, and then resumed his lunch.

Obama sat between U.N. Secretary General Ban ki Moon and Uganda’s Yoweri Museveni. Also at the Obama table were Turkish President Abdullah Gul, Colombia’s Juan Manuel Santos, King Abdullah II of Jordan, and Nigeria’s Goodluck Jonathan, in his trademark black hat.