Danny Danon, Israel's Ambassador to the United Nations, on Wednesday called for the immediate release of all hostages held by Hamas militants.

Speaking to reporters before a meeting of the UN Security Council, Danon expressed regret over this week's deadly Israeli strikes on a southern Gaza hospital that killed 20, including journalists and emergency responders.

Israel's military has said it will investigate the attack. It has offered no immediate explanation for striking twice and no evidence for an assertion that six of the dead were militants.

"We regret it. And, you know, during wartime you have such kind of incidents. But our goal is to fight terrorists, not journalists, not anyone who is not involved in terrorism," the Israeli diplomat said.

Meanwhile, Israeli and U.S. officials will meet in Washington on Wednesday to discuss post-war Gaza, even as Israel's military calls the evacuation of Gaza City “inevitable” ahead of a military offensive and with no sign of a ceasefire in sight.