India is not participating in the first UN conference in more than 20 years on a global nuclear weapons ban which opened here amid objections from major nuclear powers, the Press Trust of India (PTI) reported.

More than 120 nations in October last year voted on a UN General Assembly resolution to convene the conference to negotiate a legally binding treaty to prohibit nuclear weapons, leading towards their total elimination.

Britain, France, Israel, Russia and the US voted no, while China, India and Pakistan abstained from voting on that resolution.

The first substantive session of the conference began here Monday.

In its Explanation of Vote (EoV) given for its abstention on the resolution in October, India had said that it was "not convinced" that the proposed conference could address the longstanding expectation of the international community for a comprehensive instrument on nuclear disarmament.

India also maintained that the Geneva-based Conference on Disarmament (CD) is the single multilateral disarmament negotiation forum.

It had further said that it supports the commencement of negotiations in the Conference on Disarmament on a Comprehensive Nuclear Weapons Convention, which in addition to prohibition and elimination also includes verification.

It had said that international verification was essential to the global elimination of nuclear weapons, India feels that the current process does not include the verification aspect.

In line with its position that India articulated in the EoV, India has decided not to participate in the current conference that will run through March 31.

It will, however, continue to follow the developments in the event.

The US, France and the UK led a group of over 40 nations that are strongly protesting the UN talks.

The US' envoy to the UN Nikki Haley said the Assembly "suddenly" wants to have a hearing to ban nuclear weapons and while as a mother and daughter, she wants a world with no nuclear weapons, one also has to be "realistic".

She said given the current times "bad actors" cannot be allowed to keep their nuclear weapons while other nations try to maintain peace and safety.

"We would love to have a ban on nuclear weapons but in this day and time we cannot honestly say that we can protect our people by allowing the bad actors to have them (nuclear weapons) and those of us who are good trying to keep the peace and safety not to have them," Haley told reporters.

Haley, joined by UK's Ambassador to the UN Matthew Rycroft and her French counterpart Francois Delattre, spoke just before the General Assembly convened its first substantive session of the conference.

"We have to be realistic. Is there anyone who believes that North Korea would agree to a ban on nuclear weapons? So what you would see is that the General Assembly would go through, in good faith, trying to do something but North Korea would be the one cheering and all of us and the people we represent would be the ones at risk," she said.

She said Washington believes in the Nuclear Non-Proliferation Treaty and had reduced its weapons by 85 per cent since the treaty went into place.

She added that while the US would want to see a world without nuclear weapons, the time for it is not today and it will defend its citizens as well as its friends and allies.

"One day we will hope we no longer need nuclear weapons. But today, in this day and time, in the situations that we are in, we unfortunately don't have the ability to do that," she said.

-- BERNAMA