New Delhi, Aug 1 - Nirupama Rao took charge as India's foreign secretary Saturday and stressed that she will focus on upgrading the foreign service to enable New Delhi to play 'an even more prominent role in world affairs'.

'I have before me a complex and yet fascinating assignment,' Rao, the second woman to head India's foreign service, told reporters after moving into her new office in South Block.

'Today, in a rapidly evolving world situation, the task is to further augment our diplomatic and professional capabilities as we are called upon to play an even more prominent role in world affairs...This will be an important area of focus in my new responsibilities,' she said.

Rao succeeded Shivshankar Menon at a brief ceremony in South Block. Chokila Iyer was the first woman to serve as India's foreign secretary in 2001.

'Our foreign service counts among the best in the world,' Rao said while lauding the 'professionalism and dedication' of Indian diplomats who are required to handle issues in a 'focussed, mature and balanced' manner.