On the eve of the Nuclear Suppliers Group's extraordinary plenary meeting to decide on nuclear commerce with India, Foreign Secretary Shiv Shankar Menon will brief the current chair Germany [Images] and two other key members of the 45-nation NSG.

Menon, who arrived in Vienna [Images] on Wednesday heading a delegation that includes Ravi Grover, director, Strategic Development of the Department of Atomic Energy, will meet the representatives of the 'troika' -- Germany, South Africa [Images] and Hungary, or the current, previous and upcoming chair of the grouping, the sources said.

Indian Envoy to Geneva Venkatesh Verma will accompany Menon during the briefing at the Vienna International Centre on Wednesday evening, which comes just before the crucial two-day meeting of the NSG to consider a waiver for India, a major step in operationalising the Indo-US nuclear deal.

Earlier, India had briefed NSG members along with the Board of Governors of the International Atomic Energy Agency on July 18, 2008, and on the sidelines of the NSG meeting in Germany in the month of May.

NSG members and US envoys are tight-lipped about Wednesday's meeting and the officials from Germany told PTI that NSG is a confidential forum and only a press release will be issued after the plenary session that will consider a American draft waiver circulated to members.

According to the Indian embassy sources in Vienna, the NSG had invited India to be an observer in the two-day discussion which begins on Thursday, but it has been decided to meet the key members before the plenary meeting of NSG.

India has conveyed to the NSG members that it has an impeccable record in the non-proliferation front and that it has harmonised the export controls with that of the NSG.

It is learnt from the sources in Vienna that Austria is very much opposed to the waiver and not convinced with the American views on nuclear commerce with India as it feels this would further weaken the non-proliferation treaty.

The representatives of European Union, which has observer status in NSG, also refused to talk about the American draft which was circulated to the members recently.

Meanwhile, the Green Party of Austria and European Union are planning a protest outside the Japanese Mission where the plenary meeting to discuss India-specific safeguards and nuclear trade with India will be held.

Also, the UN's Comprehensive Test Ban Treaty Organisation is holding a press conference on online inspection regime, the ultimate instrument to verify compliance with the CTBT which will be put to test at Kazakhstan where more than 600 atomic devices were tested by erstwhile USSR till 1990.

The press conference will be addressed by the executive secretary of CTBTO, Ambassador Tibor Toth and the director of the onsite inspection division Boris Kvok.

The CTBTO had on Tuesday said test moratorium by all nations should continue so that the door to nuclear-testing can be completely closed.