Iran's mission to the United Nations said on Thursday, "the spirit of resistance will be strengthened" following the death of Hamas leader Yahya Sinwar.

"The spirit of resistance will be strengthened. He will become a model for the youth and children who will carry forward his path toward the liberation of Palestine," the mission said in a post on X. "As long as occupation and aggression exist, resistance will endure, for the martyr remains alive and a source of inspiration."

Hamas leader Yahya Sinwar, a mastermind of the Oct. 7, 2023 attack that triggered the Gaza war, has been killed by Israeli forces in the Palestinian enclave. Sinwar was named as Hamas' overall leader following the assassination of political chief Ismail Haniyeh in Tehran in July.

Lebanon's Hezbollah militant group, a Hamas ally, said on Friday it was moving to a new and escalating phase in its war against Israel. 

US President Joe Biden, who spoke to Netanyahu by phone to congratulate him, said Sinwar's death provided a chance for the conflict in Gaza to end and for Israeli hostages to be brought home.

Although Western leaders opined that his death offered an opportunity for a ceasefire, Israeli Prime Minister Benjamin Netanyahu said the war would go on until the hostages seized by Hamas militants were returned.

"Today, we have settled the score. Today, evil has been dealt a blow, but our task has still not been completed," Netanyahu said in a recorded video statement after the death was confirmed on Thursday.

Despite Western hopes of a ceasefire, Sinwar's death could dial up hostilities in the Middle East, where the prospect of an even broader conflict has grown.
(With inputs from AFP, Reuters.)