Secretary of State Antony Blinken says it is "imperative" that there be a cease-fire in Gaza after the killing of Hamas political leader Ismail Haniyeh in Iran.

Blinken made the comments while speaking at a forum in Singapore on Wednesday. His comments came just hours after Haniyeh was in Tehran for Iranian President Masoud Pezeshkian's swearing-in on Tuesday. Pezeshkian was sworn in with chants of "Death to America, Israel."

"I have seen the reports. Nothing takes more importance than getting a cease fire. In the interest of putting things on a better path. We've been working since day one to stop[this war] from spreading," he said.

Iran has not provided any details on how Haniyeh was killed. The incident is under investigation.

HAMAS LEADER ISMAIL HANIYEH REPORTEDLY ASSASSINATED

President Masoud Pezeshkian shakes hands with Hamas chief Ismail Haniyeh

Iranian President Masoud Pezeshkian, right, shakes hands with Hamas chief Ismail Haniyeh at the start of their meeting at the President's office in Tehran, Iran, Tuesday, July 30, 2024. (AP)

Israel was immediately blamed for the assassination, but no party has taken responsibility for Haniyeh's death as of Wednesday morning.

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"The fact that such a high-ranking Hamas leader was assassinated on Iranian soil was an added bonus for Israel particularly directly after he participated in the inauguration ceremony of the new Islamic Republic president," Lisa Daftari, Middle East analyst and editor-in-chief at The Foreign Desk, told Fox News.

Blinken at Aspen

Secretary of State Antony Blinken says it is "imperative" that there be a cease-fire in Gaza after the killing of Hamas political leader Ismail Haniyeh in Iran. (Aspen Security Forum via Reuters)

"It sends a clear message that Israel does not differentiate between the Islamic Republic and its proxies, Hamas and Hezbollah," she added.

HARRIS SAYS ISRAEL HAS RIGHT TO DEFEND ITSELF AS IRAN, RUSSIAN AND LEBANON CONDEMN IDF STRIKE ON HEZBOLLAH

U.S. Defense Secretary Lloyd Austin said the U.S. government would seek to ease tensions, but that it would help defend Israel if it were attacked.

Hamas said Haniyeh was killed "in a Zionist airstrike on his residence in Tehran after he participated in the inauguration of Iran’s new president."

Hamas declared Ismail Haniyeah a "martyr."

Hamas declared Ismail Haniyeah a "martyr."

"Hamas declares to the great Palestinian people and the people of the Arab and Islamic nations and all the free people of the world, brother leader Ismail Haniyeh a martyr," the statement said.

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Haniyeh left the Gaza Strip five years ago and was living in exile in Qatar. The top Hamas leader in Gaza is Yahya Sinwar, the mastermind behind the Oct. 7 terror attack on Israel. He remains alive.

Fox News' Landon Mion and Reuters contributed to this report