NEW YORK (Yonhap News) ― Ban Ki-moon, who was reelected as United Nations secretary-general here Tuesday, has had his share of success in his first term, fending off critics in the process, but he has some work cut out for him over the next five years in his second tour of duty.

A former South Korean foreign minister, Ban has so far successfully answered questions surrounding his leadership with his signature work ethic. It helped Ban get through the tumultuous events that marked the past four and a half years, including a major global financial crisis and pro-democracy movements in the Middle East and Africa.

Early in his term, Ban was besieged by critics from advanced and developing nations alike. With his philosophy based on persuasion and mediation, Ban was panned by developed countries for lacking leadership and presence and developing countries saw him as a pro-American figure.

In the summer of 2009, a Norwegian diplomat wrote in an internal memo that Ban suffered from “lack of charisma.” Last year, an official at the U.N. Office of International Oversight Services wrote in a memo, leaked to U.S. papers, that the U.N. under Ban’s watch had “no transparency” and that the agency was “falling apart and drifting into irrelevance.”

Ban has also come under fire for a perceived lack of consistency on human rights.

He is accused of taking issue with China’s Nobel Peace Prize winner Liu Xiaobo during his meeting with Chinese President Hu Jintao.

Ban has taken all this in stride, saying he welcomes criticism “as a matter of principle.” His pursuit of universal values, including human rights and democracy, also helped him win over detractors.

In May 2008, with cyclone-ravaged Myanmar seeking help, Ban persuaded its military leadership to open up and accept international aid.

Earlier this year, Ban backed democracy movements across the Middle East and northern Africa and called on the governments involved not to use force to crack down on demonstrators.

He sent U.N. forces to the Ivory Coast to handle a post-election crisis, and called on the beleaguered Libyan leader Moammar Gadhafi to “stop immediately.”

Ban traveled to eight countries in a 10-day period last year to mediate peace in Gaza. His two trips to the Gaza Strip after the 22-day Gaza War ended in early 2009 were a symbolic move that showed his commitment to peace in the region.

The U.N. chief’s tireless work ethic has also earned him respect from member states. U.N. officials say since he came on board, Ban has been traveling enough distance each month to circle the earth. Ban even spent his 67th birthday earlier this month on an Argentine coach during his South American swing.

Turning climate change into a major global issue is one of Ban’s major achievements. He has urged countries to reduce greenhouse gas emissions, saying climate change is “simply the greatest collective challenge we face as a human family.”

He has taken on climate change as his personal mission, focusing on developing clean and renewable energy technologies and on efficient use of energy. Ban has also worked on securing international help on promoting green economies in developing countries.

Ban’s efforts for climate change issues did lose some traction after a climate conference in Copenhagen in late 2009 only highlighted the chasm between developed and developing nations. But he is expected to keep pushing for changes in his second term.

Ban is also credited with establishing U.N. Women, a new organization handling issues related to gender equality and women’s rights.

Midway through the first term, Ban signed contracts with senior U.N. officials for performance goals, in an effort to ensure “transparency and accountability” at the U.N. Those have been Ban’s “watchwords” so far.

Ban will have his work cut out for him in the next term. Over the coming five years, he will have to come up with a vision that will replace Millennium Development Goals (MDGs). There are eight international development goals that all U.N. members have set out to achieve by 2015, covering eradicating poverty, cutting child mortality rates and battling epidemics.

Ban said he plans to unveil a blue print for his second term at the U.N. General Assembly in September, including a new development project.

“I will propose a comprehensive and sustainable development agenda that will surpass MDGs,” Ban said.

The U.N. chief, though, doesn’t yet have specifics on how the new agenda will be presented and pursued. A U.N. official said the work “needs more time.”

“Donor countries have suffered from the global financial crisis, and it’s not clear whether aid plans will be carried out on time,” the official said on the condition of anonymity. “If a new vision is proposed under this sort of circumstance, MDGs may lose momentum.”

The new blue print will also likely include eight main areas of strategic opportunity for the U.N., including sustainable development, improved response to major humanitarian crises, and disarmament and non-proliferation.

Ban has also said the U.N.’s role will be “strengthened” to better tackle the challenges of the 21st century.

In addition, Ban will be faced with reforming the Security Council, expanding authority of the General Assembly, and ensuring efficiency and transparency of the U.N. Secretariat.