Over 150 nations, including Iran, will get together for an international review of the Non-Proliferation Treaty, but India will not be part of the deliberations during which the US is expected to push non- signatories to sign the pact.
The conference on NPT review will kick off here on Monday and the Iran-West showdown over Tehran's nuclear programme is likely to dominate the proceedings.
India, which is not a signatory to the NPT has decided to stay out of the conference.
"We are not parties to the NPT and we will not be participating," an official at the Permanent Mission of India to the UN told PTI.
He said India would not be represented in the conference in any capacity not even as an "observer" country.
The NPT review conference is held every five years to assess the progress in reaching the goal set out in the 1970 treaty to disarm and stop the spread of nuclear weapons.
India, Pakistan and Israel have not signed the treaty and have been nudged by countries like US to sign it. North Korea withdrew from it in 2003.
The 2005 conference for the treaty ended without any concrete result and was widely regarded as a failure.
The Bush Administration garnered a great deal of hostility for diluting disarmament goals.
In this conference, the United States will push for all states that are not members of the NPT to join the agreement, which Indian considers as "unfair". Around 189 countries are presently signatories to the treaty.
"The US has had a long-standing policy of supporting the universal adherence to the NPT," Susan Burk, Special Representative of the President for Nuclear Nonproliferation told PTI, in response to a question whether Washington will
address the question of New Delhi and Islamabad's absence from the NPT.
The high-level discussions, which will be attended by 150 nations, is set to be kicked off by Iranian President Mahmoud Ahmadinejad, who is the only head-of-state who will be attending the conference.
Shortly after Ahmadinejad addresses the delegates, Secretary of State Hillary Clinton will take the floor.
The conference is taking place at a time when the US along with France, Britain and Germany are seeking support from Russia and China to impose fourth round of sanctions against Iran, an NPT member, for its alleged efforts to acquire a nuclear bomb and being in violation of the treaty.
There is concern that hostility and bickering between the nations on the Iran issue will mar the chances of a productive outcome.
Ahmadinejad is expected to criticise the elite Western nations for acquiring nuclear weapons while preventing smaller nations from doing so.
UN chief Ban Ki-moon has expressed hope that Ahmadinejad "brings some good constructive proposal in resolving the Iranian nuclear issue, that would be helpful."
Ahead of the conference, Clinton said the US has signed atomic pacts with India and other countries as it wants them to have access to civilian nuclear energy which countries are
entitled to under the non-proliferation regime.
In an interview to the NBC news, Clinton said the purpose of the Nonproliferation Treaty Review Conference is to reiterate the commitment of the international community to the three goals: disarmament, nonproliferation, the peaceful uses
of nuclear energy.
"So the vast majority of countries are coming to see what progress we can make. And this is a very high priority for President Obama. It's why he pressed so hard for the START Treaty, which he signed with President Medvedev in Prague,"
she said.
"It's why he convened the Nuclear Security Summit to highlight the threat posed by nuclear terrorism. It's why we have begun to work out deals with India and others for the peaceful use of nuclear energy, which countries are entitled
to under the nonproliferation regime," Clinton said in response to a question.
She said Iran will confuse the NPT Review Conference beginning tomorrow.