New Delhi, Feb 8 Foreign Secretary Nirupama Rao flies to The Hague on Monday to attend a three-day preparatory meeting for the Nuclear Security Summit that Washington will host in April.

Rao is India's sherpa (high representative) for the Nuclear Security Summit, an initiative of the U.S. President Barack Obama that will focus on issues like clandestine proliferation and steps to prevent nuclear weapons falling into the hands of extremists and non-state actors.

Rao is set to air India's apprehensions about nuclear terrorism and proliferation in its neighbourhood. She is expected to reiterate India's commitment to its unilateral moratorium on nuclear testing.

The February 9-11 preparatory meeting will focus on drafting a joint statement to be issued at the end of the 42-nation Nuclear Security Summit, likely April 12-13.

Prime Minister Dr. Manmohan Singh will represent India at the crucial summit, which is being held ahead of the Nuclear Non-Proliferation Treaty (NPT) review conference in May.

Prime Minister's Special Envoy Shyam Saran warned the just-concluded Global Zero Summit on nuclear disarmament in Paris about the dangers of clandestine proliferation and nuclear terrorism.

"India's security has been adversely impacted by the clandestine proliferation of nuclear weapons in its neighbourhood, often ignored and on occasion, encouraged by certain important countries," Saran said in a reference to Pakistan and to China's alleged support to Pakistan's nuclear weapon programme.

"The activities of the so-called A.Q. Khan network is an ominous reminder of the threats India continues to face in this respect," he added.