I believe that the use of disease deliberately to harm humans, animals or plants, poses the greatest danger of all weapons of mass destruction

Dr Graham Pearson, former boss of Porton Down

A number of British politicians and experts have accused the Americans of dragging their feet following the Bush administration's rejection of a new protocol in July this year.

They say the US could jeopardise moves to bring in a tough new inspection and enforcement regime.

"The danger at Geneva is that there will be an endless flow of recriminations against the United States for what it did in July and August, which will make them even more resistant to coming back on board," warned Nicholas Sims of the London School of Economics in an interview on the BBC's War Report.

New proposals

The dispute dates back to the Bush administration's decision on 25 July to veto a protocol aimed at giving the convention teeth.

Yet despite the US coming up with its own new proposals, many countries fear this will not be enough to cope with the growing threat of bio-terrorism.

The US has fallen prey to anthrax attacks

The dangers of biological weapons falling into terrorist hands is underlined by Dr Graham Pearson, the former boss of the UK Porton Down Biological Weapons Establishment.

"I believe that the use of disease deliberately to harm humans, animals or plants, poses the greatest danger of all weapons of mass destruction because it had the weakest prohibition regime in contrast to the nuclear and chemical weapon regimes," he told the BBC's War Report.

Also appearing on the programme, in his first ever broadcast interview, was Dr Serguei Popov, former head of both the Vector and Obolensk Russian biological warfare programmes.

He raised the spectre of genetically modified biological weapons, which are resistant to any conventional medicine.

"The final purpose of the programme was to create more dangerous biological agents... agents were engineered to be antibiotic resistant and even to overcome the existing vaccine," he said.

Cool reception

According to Nicholas Sims any new US proposals are not likely to be well received.

I think the protocol of biological weapons may be great on paper but it's very different going to execution

Kenneth Adleman, US presidential adviser on Defence Issues

"I would expect them to be received coolly because the United States is seen as having disqualified itself from contributing to the strengthening of the convention by its rejectionist attitude," he said.

There are worries that even after the terrorist attacks on 11 September, the United States is still not convinced that international bodies such as the United Nations can help fight the war on terror.

This follows a string of decisions by President Bush to reject other treaties, such the Kyoto agreement on global warming.

Loath to commit

Experts are also concerned that the Americans are opposing moves to toughen up the treaty to protect its own biological defence programme, as well as the US pharmaceutical industry.

But Kenneth Adleman, a presidential adviser on defence issues, said the US was loathe to commit to a new convention because it was yet to be convinced that stronger restrictions were the answer.

"I think the protocol of biological weapons may be great on paper but it's very different going to execution... Saddam Hussein has kept us out of doing any inspections, I think it's for the last three years, and that makes a mockery of those kind of conventions," he said.

The War Report is part of the BBC's weekly On The Record Programme