European Union officials say they may delay their decision on whether to allow Bulgaria and Romania to join the bloc next year.
EU officials have said they will announce next week whether the two nations will be invited to join in 2007 or the following year.
But news reports Tuesday quote unidentified EU officials who say that postponing the decision would give the two nations more time to make economic and political reforms.
The top EU enlargement official, Olli Rehn, has expressed concern that judicial reforms and anti-corruption efforts in Bulgaria are moving too slowly.
Bulgaria's Prime Minister Sergei Stanishev, however, defended the government's commitment to make what he called "painful" reforms.
He warned that delaying Bulgaria's entry into the European Union would be seen as a rejection of the nation.
Some information for this report was provided by AP and Reuters.