Europe's fiscal framework needs urgent improvement and the bloc should work towards union on it, European Central Bank policymaker Pablo Hernandez De Cos said on Monday.

"I strongly believe that a central fiscal capacity at euro area level could contribute (...) to macroeconomic stabilisation," De Cos said.

"In this respect, monetary policy would not become overburdened, as it might be in the current economic juncture," he added.

Facing a protracted growth slowdown, the European Central Bank cut rates deeper into negative territory on Thursday and relaunched fresh bond purchases with no scheduled end-date, a move that divided the normally collegial Governing Council.