Israel and the Palestinian Authority should agree to transfer control of Gaza to the UN, according to Israel's foreign minister Avigdor Lieberman.

The controversial announcement came after the Israeli Defence Forces (IDF) declared a seven-hour humanitarian ceasefire, amid outrage over a strike on a UN school in the Gaza Strip that left 10 Palestinian refugees dead.

The humanitarian window does not include the area east of the southern city of Rafah where clashes are still ongoing.

As Israel scales back its offensive, the debate focuses on the future of Gaza. The hawkish foreign minister Lieberman said that if Israel defeats Hamas, UN rule over the Palestinian territory should be considered.

"Everyone is asking, what happens after the operation ends? Suppose Israel defeats Hamas. There are a few options. International control of Gaza, by the UN, should certainly be considered."

He cited the British mandate over Palestine and the UN mandates in East Timor Kosovo as positive examples.

"We saw it works quite well there," he said. "It requires an agreement between us and the Palestinian Authority. It doesn't require consent from the UN, just from the parties involved – Israel and the PA."

The proposal was immediately dismissed by Knesset member Nachman Shai of the Labour party, who said the idea "belongs to another world".

The French foreign minister Laurent Fabius has said that Israel's right to security "does not justify the killing of children and slaughter of civilians" in Gaza. He also called for a political solution imposed by the international community on the two parties.

"Ceasefire, imposition of a two-state-solution and security for Israel – there is no other way," he said.