United Nations, June 16 (IANS) India's nominee for the post of UN chief, Shashi Tharoor, Thursday got a piece of advice from his boss, Secretary-General Kofi Annan: focus on your work and quit your post before taking up the "mission impossible" or "a job from hell".

"First of all, the Under-Secretary-General has to focus on his work," he said at a press conference at the United Nations in response to a question on whether it is possible to be under secretary-general and a candidate at the same time as he himself was once.

"He has to focus on his work as under secretary-general, and his responsibilities to the United Nations. If he or she is elected, he or she will have to resign and take up the new responsibilities," Annan said.

The secretary-general denied that on a recent trip to Asia he had suggested that his successor should be an "Asian and an outsider", criteria that would have disqualified him, as a career UN person, and would now rule out his long-time colleague Shashi Tharoor.

Annan said he had not made any specific recommendation, but merely stated that most UN members wanted the next secretary-general to come from Asia and that they seemed to be looking outside.

"It's not that I was recommending that the individual comes from outside. Obviously, the more the merrier and, as I have indicated, if an Under secretary-general is elected, he or she will have to resign. In the meantime, his or her responsibility is towards the organization, and I will have to make sure that that is respected," he said.

Asked what he would say are the essential skill set and attributes that are required based on his nearly 10 years on the job now, Annan said he would hesitate to answer at this stage as he could be accused of drawing up a tailor-made job description for one or the other of the candidates.

"But let me just say that the job is much, much wider and much bigger than chief administrative officer. You do have to be the chief diplomat of the world; you do have to take on the negotiations; there are lots of other issues that the secretary-general gets involved in, and it is not just as an administrative officer. But I think I should be careful not to define it strictly." He said.

Annan agreed with a questioner that the top UN job was like 'a mission impossible' at times. "...and as I told you when I took the job, someone described it as a job from hell. That was one of the first cables I got, and I don't think he was far wrong."