The risk of avian flu being brought into Switzerland by migratory birds is low, according to a panel of government experts.
However, the government on Friday decided to extend its ban of poultry imports from Asian countries to Russia and Kazakhstan.
Russian and Kazakh health officials revealed last week that bird flu had been discovered in several regions.
The Russian authorities say that migratory birds from southeast Asia could have brought the virus with them as they flew to Siberia for the summer.
Some reports say the strain found in Siberia was the deadly H5N1, which is known to cross from birds to humans and has killed at least 50 people in southeast Asia since 2003.
The Federal Veterinary Office said Friday's decision was of a formal nature, since Switzerland does not import any poultry products from these two countries.
It comes three days after the Office organised a meeting in Bern of 15 ornithologists, human-health experts and animal-disease specialists.
The aim was to exchange information and discuss the likelihood of avian flu being carried into Switzerland by birds migrating from Siberia for the winter.
Matthias Kestenholz from the Swiss Institute of Ornithology at Sempach was one of two ornithologists invited to Tuesday's meeting.
He told swissinfo that if it was confirmed that the H5N1 strain was responsible for the outbreaks in Russia and Kazakhstan, the disease was then theoretically a step closer to arriving in Switzerland.
"There are two types of migratory water birds which fly from Siberia to Switzerland for the winter: the pochard and the tufted duck," said Kestenholz.
Around 80,000-100,000 pochards and 150,000-180,000 tufted ducks flock to Swiss lakes and rivers from October onwards.
However, Kestenholz said that it was highly unlikely that these birds would be infected when landing on Swiss shores, given the aggressive nature of the disease.
"If they were sick when they left Siberia, it is highly unlikely they would be fit enough to fly nearly 4,000 kilometres to Switzerland," Kestenholz said.
He added that if sick birds did survive the journey, they would not come into close contact with either poultry or humans.
"These are not the kind of birds that people can feed; they remain on the water far from lakeshores and riverbanks," he said.
For infection to occur, the contact between a diseased bird and another being would have to be close and possibly over a longer duration of time, Kestenholz said.
He added that if it was confirmed that H5N1 was found in Russia and Kazakhstan, it would be up to the Veterinary Office to make an appropriate risk assessment and that there would be ample time to do so, as the first birds would not arrive until at least October.
Marcel Falk of the Veterinary Office confirmed that poultry imports from southeast Asian countries affected by avian flu were prohibited.
Falk said a de facto ban was already in place for Russia and Kazakhstan.
But he also stressed that it was important not to overplay the significance of the meeting with specialists.
In a separate development, the Geneva-based World Health Organization (WHO) announced earlier this week that it was engaged in talks with Swiss pharmaceutical firm Roche about building a stockpile of Tamiflu, the anti-bird flu drug.
WHO Director-General Lee Jong-woo said the intention was to create a reserve of at least one million doses. The WHO currently has 125,000 doses at its disposal.
swissinfo, Faryal Mirza
The H5N1 strain of avian flu has been responsible for at least 50 human deaths across southeast Asia, who were infected through contact with diseased birds.
Outbreaks of avian flu were recently discovered in Russia and Kazakhstan.
It has yet to be confirmed whether type H5N1 was involved.
It is forbidden to import poultry and poultry products, such as eggs and feathers, to Switzerland from the following countries:
In compliance with the JTI standards