European Union (search) foreign ministers on Tuesday declared the spread of bird flu from Asia into Europe a global threat requiring broad international cooperation to contain.

They also called on the EU Executive Commission (search) to accelerate steps to draft stronger rules against the virus, which in recent days has been discovered in Greece, Romania and Turkey, leading to bans on poultry from those countries.

The deadly H5N1 (search) bird flu strain has swept poultry populations in large swaths of Asia since 2003, jumping to humans and killing at least 61 people — more than 40 of them in Vietnam — and resulting in the deaths of tens of millions of birds.

Its spread westward by migrating wild fowl has intensified fears the virus may mutate into one that can be easily transmitted among humans — a development experts fear could provoke a global epidemic that puts millions of lives at risk.

The foreign ministers were to issue a statement saying they recognize bird flu poses a serious, global health threat if it shifts from birds to human beings and one "that requires a coordinated international reaction."

The EU stepped up biosecurity measures and installed early detection systems along the migratory paths of birds to prevent contamination of domestic flocks.

But there are concerns that European nations lack stockpiles of vaccines and anti-virals to cope with a major outbreak.

The World Health Organization (search) recommends governments keep enough anti-viral drugs and regular human flu vaccines to inoculate at least 25 percent of their populations.

European officials say the 25 nations in the EU, as well as Iceland, Norway and Liechtenstein, have only 10 million doses for an area with 500 million people. That's just 1 percent of the population.

Stockpiling vaccines is difficult as flu viruses can mutate quickly.

There is no human vaccine for the current strain of bird flu but scientists believe the Tamiflu drug may help humans fend off the virus.