Israeli Foreign Minister Israel Katz on Thursday said Hamas leader Yahya Sinwar was killed by Israel's military forces on Wednesday.

"The elimination of Sinwar creates an opportunity for the immediate release of the hostages and a potential change that could lead to a new reality in Gaza—without Hamas and without Iranian control," he said in a statement, according to NBC News.

Israeli Prime Minister Benjamin Netanyahu said in a press statement that although Sinwar's death is "a significant milestone," for Israel "the war is not yet over."

"Hamas will no longer rule Gaza. This is the beginning of the day after Hamas, and this is an opportunity for you, the residents of Gaza, to finally break free from its tyranny," Netanyahu said.

Israel Defense Forces Chief of the General Staff Lt. Gen. Herzi Halevi said in a video statement that they "will not stop until we capture all the terrorists involved in the Oct. 7 massacre and bring all the hostages home."

Earlier in the day, the Israel Defense Forces said they were investigating the "possibility" that Sinwar was among three militants killed in an operation in the Gaza Strip, whose identities they could not confirm at the time.

"The forces that are operating in the area are continuing to operate with the required caution," they added in a social media post. CNBC could not independently verify the report.

In a press statement, President Joe Biden commended the news, adding that he "will be speaking soon with Netanyahu and other Israeli leaders to congratulate them, to discuss the pathway for bringing the hostages home to their families, and for ending this war once and for all, which has caused so much devastation to innocent people."

As the news broke, Biden was en route to Germany to meet with allied countries for talks on Ukraine and the Middle East.

Vice President Kamala Harris echoed the president's sentiments at a campaign stop in Milwaukee.

"Hamas is decimated and its leadership is eliminated," Harris told the press. "This moment gives us an opportunity to finally end the war in Gaza and it must end such that Israel is secure, the hostages are released, the suffering in Gaza ends, and the Palestinian people can realize their right to dignity, security, freedom and self-determination."

Sinwar's killing is a "seismic event that changes the nature of this conflict," U.S. State Department Spokesperson Matthew Miller said, accusing the Hamas leader of having been "the chief obstacle" to getting a ceasefire agreement in Gaza.

"Over the past few weeks, there have been no negotiations for an end to the war because Sinwar has refused to negotiate," Miller said. "We now see an opportunity with him being removed from the battlefield, being removed from the leadership of Hamas, and we want to seize that opportunity."

Previously leader of Hamas in the Gaza Strip, Sinwar, 62, assumed overall command of the Iran-backed organization in August, following the assassination of former political chief Ismail Haniyeh. His death marks the most dire blow Israel has dealt Hamas in the yearlong conflict sparked by the Palestinian militant group's Oct. 7 terror attacks on the Jewish state, which Israel has accused Sinwar of orchestrating.

The offensive propelled the Israeli government of Netanyahu to launch a retaliatory operation in the Gaza Strip in a bid to dismantle the military capabilities and leadership of the Palestinian group.

More than 42,000 Palestinian people have been killed in the Gaza Strip since Oct. 7, according to the local Health Ministry, while 101 people abducted from Israel are believed to remain hostages of Hamas in the enclave. The Hostages Families Forum, representing families of the captives, welcomed the Thursday news on social media, but urged the Israeli government to use this opportunity as leverage to secure the return of hostages.

The war in the Gaza Strip has expanded to include direct hostilities between Israel and Iran, along with clashes between the Jewish state and other Tehran-backed factions, such as Yemen's Houthis and Lebanese group Hezbollah — whose leader Hassan Nasrallah was killed last month by Israeli forces in an air attack in Beirut.

Markets have been mired in the Middle East conflict, which now poses substantial risks to oil supplies, if Israel answers the latest Iranian hostilities with strikes targeting Tehran's energy infrastructure and export facilities.

Houthi maritime attacks against ships it claims are linked to Israel, the U.S. or the U.K. — which have also been carried out against unaffiliated vessels — have meanwhile disrupted a key commercial route in the Red Sea that links Asia-Pacific and the Mediterranean.

Sinwar was born in a refugee camp in the Gaza enclave and spent at least 22 years of his adult life in Israeli prisons. He had been sentenced to life in 1989 for directing the killing of two Israeli soldiers and four Palestinians that he believed to be collaborators, having already made a name for himself as "the Butcher of Khan Yunis" for his hunting down of Palestinians he suspected to be working with Israel.

He was released early, however, in a highly controversial prisoner swap in 2011 that saw more than 1,000 Palestinian prisoners exchanged for one Israeli soldier, Gilad Shalit, who had been abducted by Hamas five years prior.

Sinwar later said in interviews that he used his time in prison to learn to speak, read and write in Hebrew, and to understand the psychology and behavior of his Israeli captors. In 2015 he was designated a terrorist by the U.S. government.

The International Criminal Court in May said it was filing arrest warrant applications for Sinwar and Haniyeh for war crimes and crimes against humanity. It simultaneously filed arrest warrant applications for war crimes and crimes against humanity for Netanyahu and Israeli Defense Minister Yoav Gallant.

It is unclear who would succeed Sinwar as leader of Hamas and what impact his death could have on stalled negotiations for a cease-fire.