Translate the following English sentence to French:
"The action plans that Tampere accepted and stated should continue, in spite of their inability to cope with the complexity of the problem, could nevertheless be improved until the European Union can equip itself with an asylum and immigration policy of its own."
Les plans d' action que Tampere a accueillis et demandé de poursuivre, peuvent, malgré leur fragilité face à la complexité du problème, être entre-temps améliorés en attendant que l' Union européenne se dote d' une politique d' asile et d' immigration propre.