GENEVA - The United Nations vented frustration on Thursday at the lack of progress at the world's only multilateral disarmament negotiating forum, calling on its members to show more flexibility and get down to work.

The U.N.-backed Conference on Disarmament (CD) has been unable to launch negotiations to halt global production of nuclear bomb-making fissile material so far this year.

Pakistan has refused to join a required consensus at the 65-member forum, insisting that it needs to keep open the fissile option to keep pace with its nuclear-armed rival India.

The talks have regressed and risk becoming irrelevant if they don't keep in tune with international efforts to cut weapons arsenals, warned Sergei Ordzhonikidze, head of the U.N. in Geneva who serves as secretary-general of the conference.

What we see is not zero, but it is minus, he said in a blunt speech on Thursday. We have done nothing.

I don't know what to tell the Secretary-General (Ban Ki-moon) when he asks what is going on in the CD except to say, 'I am sorry Mr. Secretary-General, nothing is going on'.

The stalemate has been a blow to the Obama administration's efforts to revive global disarmament as it also seeks to agree a successor Strategic Arms Reduction Treaty (START) with Russia. Those talks are now in their final round in Geneva.

On behalf of Ban, Ordzhonikidze appealed to members to be a little more flexible and overcome the wrangling over which items to tackle in 2010, known as the programme of work.

It is not the finalisation of the elaboration of any treaty, it is just the programme of work, he said.
In addition to fissile material (highly-enriched uranium and plutonium), the other core issues on the table are talks on wider nuclear disarmament, halting an arms race in outer space and negative security assurances -- promises by nuclear powers not to use atomic weapons on non-nuclear states.

Pakistan's envoy Zamir Akram has invoked its right to raise other issues including the use of missiles as weapon delivery systems and regional arms control issues at the annual session.

(Editing by Jonathan Lynn and Myra MacDonald)