Politicians defer position on nuclear ban

Parliamentarians have responded carefully to Australia joining the US in boycotting UN talks on a prohibition of nuclear weapons.

Federal politicians have trodden carefully around the issue of nuclear weapons as Australia joins the US in a boycott of ban negotiations.

Australia is part of a US-led coalition of 40 nations not participating in United Nations talks on a legally binding instrument to prohibit nuclear weapons.

At least 113 nations are joining the discussions which run until Friday.

"I think we have to tread in that space exceptionally carefully," Liberal senator Eric Abetz told reporters on Tuesday.

"Nuclear weapons - of course, the world would be better off without them, but the issue now is to deal with the realities."

Senator Abetz also thought Australia should consider obtaining nuclear-powered submarines.

Labor senator Murray Watt said his party was disappointed Australia would not participate in negotiations.

"Australia, particularly when Labor has been in power, has had an excellent record in nuclear non-proliferation," he said.

"We think it's important that Australia attends the conference that's going to be discussing these matters and express deep concern about the continued use of nuclear weapons."

Research by disarmament advocate Ploughshares Fund finds nine countries in the world possess nearly 15,000 nuclear weapons.

Russia and the United States account for 93 per cent of that total.

The newly appointed US ambassador to the UN, Nikki Haley, on Monday called for countries to be realistic when approaching the issue of nuclear weapons.

"Is there anyone that believes that North Korea would agree to a ban on nuclear weapons?" she asked.

The Australian Senate has urged the government to join the UN talks.

But crossbench senator David Leyonhjelm said negotiating on nuclear weapons was not a practical question.

"Countries have got nuclear weapons and the idea that you can remove them somehow is fanciful ... I think you have to accept the status quo as the status quo," he said.