At the Seoul Foreign Correspondents Club, Ban said, "I believe that promises made must be promises kept."
Ban was referring to eight Millennium Development Goals on hunger, poverty, health, shelter and environmental issues agreed to by world leaders in 2000.
In September, 140 world leaders reaffirmed their commitments to reaching target objectives by 2015.
As the Group of 20 leaders negotiated in South Korea, Ban said, "The MDGs (millennium development goals) are about building sustainability, building global growth, building a better world."
He called the goals "Weapons of mass construction."
With 64 million people falling into extreme poverty in 2010, Ban said, "The economic crisis should not be an excuse to do less. It is a reason to do more. We must be accountable to the most vulnerable," he said.