Israeli Prime Minister Benjamin Netanyahu appeared to confirm that new negotiations were underway to recover hostages held by Hamas, after a source said Israel’s intelligence chief met the prime minister of Qatar, a country mediating in the Israeli-Palestinian conflict.

In a televised press conference a day after Israeli forces mistakenly killed three of more than 100 hostages held by Hamas, Netanyahu called the conflict an existential war that must be fought until victory, despite pressure and costs, and said Gaza would be demilitarized and under Israeli security control.

He said Israel’s offensive in Gaza had helped clinch a partial hostage-release deal in November and vowed to maintain intense military pressure on Hamas.

“The instruction I am giving the negotiating team is predicated on this pressure, without which we have nothing,” he said, according to Reuters.