GENEVA Iran spearheaded opposition on Monday to a U.S. and Russian-backed plan to postpone fixing a date to destroy the world's last known stocks of live smallpox virus.
A debate over when to destroy stocks held in the United States and Russia has rumbled on for 25 years and resurfaced late last week.
Lengthy talks had yet to come up with a compromise on Monday between those such as Iran that want the stocks destroyed and the United States and other powers that say a decision should be put off for another five years.
"You could say Iran is using this issue," a source close to the discussions told Reuters on condition of anonymity. "But it isn't just Iran. It's more or less a division between the developed and the developing world."
Iran is at odds with the United States and other powers over its nuclear programme, which Tehran has insisted is only aimed at generating electricity, not atomic weapons.
The source said a decision had to be taken on Tuesday at the latest, the final day of the World Health Organization's annual meeting in Geneva, but added: "They could decide not to decide".
The United States has argued more research is needed into vaccines against the disease eradicated more than 30 years ago. It also wants guarantees that all other stocks have been destroyed or transferred to their two official repositories.
Some countries have argued technology exists to develop vaccines and anti-virals without a live virus and those on both sides of the divide have raised concerns about germ warfare.
Countries, such as Iran, have said the risk of stockpiles falling into the wrong hands was a reason to destroy them now.
The United States has said the virus samples were needed to create vaccines as the population no longer had immunity to the disease.
In February, Siga Technologies Inc was awarded a U.S. government contract for a smallpox antiviral.
Smallpox, an acutely contagious disease, was eradicated worldwide in 1979, the WHO certified, two years after the last case was detected in Somalia.
In addition to the U.S. and Russian stores of smallpox virus, the WHO maintains a vaccine emergency stockpile of 32.6 million doses kept securely in Switzerland.
On Monday, Iran proposed a vote on the smallpox issue, an unusual step as the 193-member United Nations agency reaches most decisions by consensus. Other nations rejected Iran's suggestion in favour of setting up a working group to seek a compromise.
The other business of the annual WHO assembly was largely complete, officials said on Monday.
A previously-agreed landmark deal to improve preparedness for a flu pandemic by allowing virus samples to be shared globally in exchange for vaccines produced from them was expected to be rubber-stamped, one source said.
At the weekend, the WHO also unanimously endorsed a resolution on the prevention and control of non-communicable diseases (NCDs), which include cancer, heart disease and diabetes.
"It's (NCDs) not just an enormous health problem, it's becoming a major problem with a significant social, economic dimension because of links to poverty," Ala Alwan, assistant director-general of the WHO, told reporters on Monday.
(Editing by Janet Lawrence)