United Nations, Jan 3 (IANS) Pledging "continuity with change", Ban Ki-moon Tuesday took over as the eighth United Nations secretary general, with former Indian diplomat Vijay Nambiar as his chef of staff.

Ban, who succeeded Kofi Annan Jan 1, smiled broadly as he entered the towering landmark UN building on New York's East River for his first official day of work, passing an honour guard and welcomed with applause from staff.

"I am very much overwhelmed by all this warm welcome," he told a crowd of reporters. "Your presence this morning is a vivid proof that the United Nations is much alive in the frontline addressing all the challenges and issues and trying to give hope to all the people around the world," he said.

Besides Nambiar, who brings years of experience in diplomacy - both within and outside the UN - to the job, Ban has named Michelle Montas, an award-winning journalist from Haiti, as spokesperson.

As special advisor to Annan, Nambiar undertook a number of sensitive assignments, including travelling to the Middle East following the war between Israel and Hezbollah.

Before joining Annan's team in March, Nambiar was deputy national security advisor to the Government of India and head of the National Security Council Secretariat.

He served as India's permanent representative to the UN in New York from May 2002 to June 2004. Earlier as ambassador of India, he served in Pakistan (2000-2001), China (1996-2000), Malaysia (1993-1996) and Afghanistan (1990-1992). He was also India's ambassador in Algeria from 1985 to 1988.

During the course of his professional career in the Indian Foreign Service (IFS), the 63-year-old diplomat had served in numerous bilateral and multilateral appointments in Beijing, Belgrade and New York during the 1970s and 1980s.

Nambiar joined the IFS in 1967 and spent his early years in the diplomatic service specialising in the Chinese language serving in Hong Kong and Beijing. He also served during the mid-1970s in Belgrade, Yugoslavia.

Announcing Nambiar's appointment Sunday, Ban said, "I have known Mr. Nambiar for a long time and we share deep confidence and respect for each other."

Montas, the current head of the French unit of UN Radio, served previously as spokesperson for the General Assembly president in 2003.

These "appointments will serve as a solid basis for establishing my team and pursuing a programme of reform of the Secretariat to provide continuity along with change", said Ban promising to name more members of his team in the coming days.