Italy on Thursday described the death of hostage Giovanni Lo Porto a "tragic and fatal error by our US allies" but said "terrorists" were entirely to blame.
The foreign ministry said in a statement that Lo Porto had died "because of the tragic and fatal error by our American allies, recognised by President (Barack) Obama".
It added: "The responsibility for his and Warren Weinstein's death however... was entirely the terrorists against whom we confirm Italy's commitment alongside our allies."
The Italian statement came after Obama revealed on Thursday that Lo Porto and fellow aid worker Weinstein were killed inadvertently in a covert operation against Al-Qaeda on the Afghanistan-Pakistan border in January.
Obama offered an emotional apology and said he took "full responsibility" for the tragedy.