U.S. Secretary of State Antony Blinken said today the United States was not involved in the assassination of Hamas leader Ismail Haniyeh, and reiterated the importance of a ceasefire in Gaza.

“This is something we were not aware of or involved in. It’s very hard to speculate,” Blinken said in an interview with Channel News Asia during a visit to Singapore.

Iran’s Revolutionary Guards confirmed Haniyeh’s death, hours after he attended a swearing-in ceremony for the country’s new president.

Haniyeh, who leads the Palestinian militant group and is normally based in Qatar, has been the face of Hamas’s international diplomacy as the war set off by the Hamas-led attack on Israel on Oct. 7 has raged in Gaza.

“I’ve learned over many years never to speculate on the impact one event may have on something else,” Blinken said when asked what impact Haniyeh’s death might have on the war.

The assassination, less than 24 hours after Israel claimed to have killed a Hezbollah commander it said was behind a deadly strike in the Israeli-occupied Golan Heights, could be a major setback for chances of a ceasefire agreement in the 10-month-old war.

Blinken, who has been in Asia since late last week, said a ceasefire and the release of hostages being held in Gaza was crucial and the United States would do everything to make that happen.

“It’s vitally important to hopefully put things on a better path for more enduring peace and more enduring security, so that focus remains.”