UNITED NATIONS - The UN Secretary-General Ban Ki-moon on Friday highlighted the challenges and lessons learned by the world's body from Hurricane Sandy, calling for more actions to deal with climate change.

In a briefing to an informal meeting of the UN General Assembly on the impact of Hurricane Sandy, Ban said emergency situations can lay bare where people may have been operating on flawed assumptions and must do better.

"Such was the case over the past two weeks. The UN continued to provide its vital global services despite major disruption," he said. "At the same time, where there were mistakes - there must be lessons. We are determined to work with all of you to learn and move forward."

Originating in the Atlantic Ocean in late October, Hurricane Sandy caused deaths and destruction across the Caribbean region and the eastern coast of the United States.

In the wake of the hurricane, the UN New York headquarters were being closed for three days straight with most scheduled meetings canceled.

The UN complex suffered damage due to high wind and flooding, which affected communications and other infrastructure.

"Throughout the crisis, my overriding concerns, and that of senior management, were to ensure the safety of delegates and staff, and to resume normal operations as early as possible," Ban said. "I am pleased to inform you that there have been no reports of injuries to staff members and their dependent."

At a meeting of the UN General Assembly's Fifth (budgetary) Committee held on Monday, several delegations, led by Ambassador Mourad Benmehidi of Algeria, criticized senior UN officials' reaction last week to Hurricane Sandy, citing a "total breakdown in communications" with diplomatic missions to the headquarters.

In response, Ban said he fully understands the frustration of many delegates and staff members hoping for guidance, critical information or even just a reassuring word during the disaster. "We are looking closely into what worked and what did not work during the response, and are determined to fix whatever went wrong."

Ban hence raised the issue of climate change, saying: "Extreme weather due to climate change is the new normal."

Challenges before the international community remain clear and urgent: a reduction in greenhouse gas emissions, strengthening for adaptation to the even larger climate shocks expected in the future, and to reach a legally binding climate agreement by 2015, said the UN chief.

"This is an opportunity, not just a burden. It is a chance to steer the world on a more sustainable path - creating the jobs and energy systems and other foundations for long-term prosperity and stability for all," Ban said.

"This should be one of the main lessons of Hurricane Sandy," he added. "Let us make this wise investment in our common future."