"I am urging the leaders to address these matters with a sense of urgency," Ban said after meeting with Thai Prime Minister Yingluck Shinawatra, whose government has been struggling to contain the country's worst floods in five decades.
"We do not have any time to waste," Ban said before visiting a centre for flood victims in Bangkok.
The UN chief urged world leaders to clarify a new Kyoto Protocol at the climate conference starting November 28 in Durban.
He also urged member states to "make clear guidelines and deliver on what has been pledged in Copenhagen in 2009, that is 30 billion dollars by the end of 2012 for developing countries in their efforts to adjust to climate change," Ban said.
Unusually heavy monsoon rains triggered floods that claimed 564 lives over the past three months in Thailand, which has made no appeal for emergency assistance from the international community, including the UN, which has offered its help.
Yingluck said it was not yet the time to request foreign aid.
"Before we ask for assistance from others, we need to diagnose the problems," she said.