With divisions among scientists about the wisdom of inoculating birds, scientists were seeking to lay down strict conditions before allowing the Netherlands and France to go ahead.
Meanwhile, alarm over the spread of the virus increased when the H5N1 strain was identified in three dead swans found in Hungary last week, making it the seventh EU country to confirm a case. Slovakia reported a suspected outbreak and the number of cases of H5N1 bird flu in Germany rose to 103.
With no let-up in the spread, nations remain divided over tactics in seeking to head off any infection of the commercial poultry sector - the main threat facing Europe immediately.
Dominique Bussereau, France's Agriculture Ministers, said he expected to get the green light to vaccinate 900,000 geese and ducks in three départements. The Netherlands wants farmers of more than five million free-range birds to inoculate or confine them.
Diplomats expect the measures to be approved today subject to conditions, but the length of time taken to reach an agreement underlines the doubts many have about the effectiveness of vaccination.