He was the younger brother of Yahya Sinwar, the former Hamas leader killed by Israel last year. Hamas did not immediately respond to the claim of his death.

The trip had been planned for Sunday ahead of a June conference, backed by France and Saudi Arabia, to urge the creation of a Palestinian state.

Hamas leaders said they were reviewing a ceasefire deal proposed by the Trump administration that had already received Israel's stamp of approval.

Israel is blocking all but a trickle of humanitarian aid from entering Gaza, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said, with almost no ready-to-eat food entering what its spokesperson described as "the hungriest place on earth".

A series of exchanges marked a new low point in the relationship between France and Israel, which accused the French president of “a crusade against the Jewish state.”