Translate the following English sentence to French:
"It has unfortunately been observed, I have to say, that the European Union has failed to reach agreement internally on specific tax measures. This indicates how difficult these dossiers are."
Il a été remarqué, malheureusement, que l' Union européenne n' est parvenue à aucun accord interne concernant certaines mesures fiscales, ce qui prouve combien ces dossiers sont délicats.