Geneva: Pakistan came under severe pressure from the major nuclear powers on Thursday to end its defiance of 64 other countries in blocking international disarmament talks.

Despite warnings that the blockage could discredit the world’s principal disarmament forum, Pakistan’s ambassador Zamir Akram held firm against an unusual joint offensive by Britain, China, Russia and the United States.

Citing unspecified national security concerns, Pakistan has been alone in stalling since the 65 states took a landmark decision in May to break more than a decade of deadlock in the Conference on Disarmament (CD) by agreeing on a work plan for 2009.

US representative Garold Larson on Thursday criticised the blockage as “procedural fault finding,” underlining that there was room to deal with national security issues in the talks once they get under way.

“We therefore are left wondering as to the motivations of those who have blocked agreement since we reconvened in early August,” he said.

“The international community is watching and will draw the correct conclusions as to whether the CD is to regain its relevance and stature as the world’s multilateral negotiating forum, or revert to inertia and the failed patterns of the past,” Larson added.

China’s ambassador Wang Guangya called for work to start as soon as possible: “We must do it, we must start work.”

Russian ambassador Valery Loschinin said: “In our view this is a compromise that is sufficiently balanced and should be acceptable to everyone.”

“The CD is on a cliff,” Japan’s ambassador Akio Suda commented.

But Akram reiterated his country’s objections to part of the structure of the talks that has been accepted by all the other countries in recent weeks, stating: “That remains our official and formal stance.”

The talks are slated to include full “negotiations” on an international ban on the production of new nuclear bomb-making material, as well as discussions on full nuclear disarmament, the arms race in outer space, and security assurances for non-nuclear states.