Israeli and Iranian officials are taking part in a nuclear non-proliferation meeting in Brussels on Monday, in the hope of paving the way for a full international conference in the next few months on banning nuclear arms and other weapons of mass destruction from the Middle East.

A handful of officials from both Israel and Iran are involved in the two-day event, ostensibly in their capacity as private citizens, in what was billed as an academic seminar.

But the delegations are led by senior officials and have the permission of their respective governments to take part in an informal discussion with representatives from about 10 Arab states, US officials and European moderators to explore the possibility of holding a UN-sponsored conference on establishing a WMD-free zone in the Middle East.

The Israeli team is led by Jeremy Issacharoff, an ambassador for strategic affairs at the foreign ministry; the chief Iranian representative is Ali Asghar Soltanieh, the country's long-serving ambassador to the International Atomic Energy Agency in Vienna. Also taking part is Jaakko Laajava, the Finnish diplomat tasked by the UN secretary general to organise the planned conference in Helsinki.

In contrast to the ever-worsening sabre-rattling over the Iranian nuclear programme, the mood at the meeting, convened by the EU Non-Proliferation Consortium, was described by one participant as "respectful and positive".

Mark Fitzpatrick, a non-proliferation expert from the International Institute for Strategic Studies and former state department official, said "there were no fireworks and no denunciations" at the conference. That marks an improvement over a similar event held last year, when the tone was described as mutual finger-wagging. However, it was unclear from the meeting whether the Helsinki conference would go ahead on schedule in December.

Washington has been going out of its way in recent weeks to brief observers that the talks would be postponed, although it was not clear whether that was a tactic to avoid reports emerging in the midst of the election campaign that the US had pressured Israel to sit at the negotiating table with Iran.

Two junior US officials are taking part in this week's meeting but have so far said little. One source said Washington's intentions would be clear once the elections were over, but noted that participants had taken to calling the UN-sponsored event the 'Helsinki conference', rather than the '2012 conference', as uncertainty increases over its timing.

Israel's official position is neither to confirm nor deny its widely reported nuclear arsenal, and it would consider signing the nuclear Non-Proliferation Treaty, thereby renouncing its right to have such weapons, only if its existence and its right to exist had been guaranteed by its neighbours and the region was at peace.

Nevertheless, European mediators hope the UN conference will initially represent a way of coaxing Israel into more transparency in return for continued Arab and Iranian abstinence from nuclear weapons under the increasingly strained treaty.