Hamas has confirmed that its leader, Yahya Sinwar, was killed by Israeli forces in Gaza and reiterated its stance that hostages the militant group took from Israel a year ago will not be released until there is a cease-fire in Gaza and a withdrawal of Israeli troops.

President Joe Biden said he’s sending Secretary of State Antony Blinken to Israel as part of efforts to end the conflict.

Sinwar’s demise leaves Hamas with no clear successor. With the world bracing for Israel’s expected retaliation against Iran for an Oct. 1 missile barrage, Netanyahu scored another coup after the assassination of Hamas political chief Ismail Haniyeh in July and Hezbollah’s leader Hassan Nasrallah last month.