South Korea's Ban Ki-moon, succeeding Kofi Annan as the next head of the United Nations, on Thursday took oath of office with the promise to work to achieve highest ethical standards as also highest levels of efficiency, competence and integrity in the organisation.

Though he did not explicitly say, apparently the oil-for-food scandal and irregularities found in the procurement during the latter half of Secretary-General Annan's term were at the back of his mind.

On the political front, he pledged to strengthen the three pillars of the world body including security development and human rights, which, he said, would allow the UN to be a more peaceful, a more prosperous and more just world for the succeeding generations.

But Ban, who formally takes over on January 1, said his first priority would be restore trust in the organisation.

"I will seek to act as harmoniser and bridge-builder," he said.

Photograph: AFP/Getty Images | Text: PTI