“No country should live in fear of terrorists coming into people’s homes, gunning them down in the street, dragging them across the border and making hostages of them,” Blinken said on Sunday.
“That is intolerable for any democracy.”
The Holocaust survivor kidnapped by Hamas is not the first to have fallen victim to the terrorist group, it is understood.
In February last year, Naomi Perlman, 91, died after succumbing to shrapnel wounds she sustained in her leg after a Hamas rocket hit her home in Ashkelon.
Her caregiver, Soumya Soutash, was killed in the same strike.
Meanwhile, Blinken added, the US was trying to confirm whether American citizens were among those who had been killed and captured by Hamas.
“We’re working overtime to verify that. At the same time, there are reports of missing Americans, and there again, we’re working to verify those reports,” he said.