Khaled Meshal, pictured speaking at a 2017 conference in Qatar, will "very likely" become the leader of Hamas if the Israeli military can confirm the death of Yahya Sinwar in a strike in Gaza. KARIM JAAFAR/AFP via Getty Images

A former terrorism analyst at the Treasury Department said if reports are confirmed that Israel took out the mastermind of Hamas' Oct. 7 attack, the United States must pressure Qatar to extradite his likely successor to the United States or Israel.

The Israel Defense Forces said Thursday that they are investigating the possibility that Hamas leader Yahya Sinwar was one of the three "terrorists" killed in a recent strike in Gaza.

They were waiting for DNA tests to confirm the death but they say it is of 'high likelihood' that it was him that was killed, the Times of Israel reported.

Sinwar, the political and military leader of Hamas, took over leadership of the terror group after the July assassination of Ismail Haniyeh in Iran.

"IF Sinwar is dead, here's what needs to happen: When Qatar-based Hamas leader Khaled Meshal very likely takes over the organization, the US needs to put massive pressure on Doha," Jonathan Schanzer, a senior vice president for research at the Foundation for Defense of Democracies, wrote on X.

He said Qatar should be "forced to freeze" Meshal's assets and then extradite him to the U.S. or Israel.

"But before he is sent elsewhere to account for his crimes, he must be compelled to surrender on behalf of the Hamas terror organization," Schanzer said.

He said taking Meshal into custody "would mark the end of war in Gaza. It wouldn't mean the end of Hamas. But it could begin a process of de-Hamasification in Gaza."

"In other words, if Sinwar is dead, the last remaining recognizable leader of Hamas is based in a country that is purportedly a US ally," Schanzer said.

"Qatar should be compelled to end the war with the leverage it has over Khaled Meshal, who has been living in Doha for years," Schanzer said.