U.N. Secretary-General Ban Ki-moon on Thursday called on Syria's president to stop the bloodshed in his country and engage in dialogue before it's too late.

Since protests began in Syria in March against more than four decades of rule by President Bashar Assad's family, about 1,400 civilians have been killed, according to human rights activists there.

Speaking to journalists in Brazil, his last stop in a South America tour that included Colombia, Argentina and Uruguay, Ban called on Syria's president to "stop killing people" and told reporters that he'd urged Assad to "engage in inclusive dialogue and to take bold measures before it's too late."

Ban also promised that the United Nations would work to ensure the success of next year's U.N. Conference on Sustainable Development, known as Rio+20, to be held in Brazil next year. Failure to agree on a global framework for dealing with climate change and ensuring manageable growth will have drastic consequences, he said.

"We are now facing food security, energy security, water scarcity and health issues," he said. "All these issues are interlinked. We need to connect the dots, look at the issues in a more comprehensive way."

Brazil hosted the first international summit about the environment in 1992, setting the parameters for future debates on climate change. The conference scheduled for June 2012, two decades later, will seek to renew international commitment to manageable growth.

Asked about Brazil's aspiration to join the U.N.'s Security Council as a permanent member, Ban said only that Latin America should have greater representation on the council.

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