"Hamas's number three Marwan Issa was killed in an Israeli operation last week," National Security Advisor Jake Sullivan said as he gave a readout of a call between President Joe Biden and Prime Minister Benjamin Netanyahu.

Sullivan said Israel had also "broken a significant number of Hamas battalions, killed 1000s of Hamas fighters including senior commanders."

"The rest of the top leaders are in hiding, likely deep in the Hamas tunnel network, and justice will come for them too," he added.

Israel's military said on March 11 that an air strike on an underground compound in central Gaza on March 9-10 had targeted Issa, describing him as one of the planners of Hamas's October 7 attack on Israel.

Issa was a deputy of Mohammed Deif, who heads Hamas's armed wing, the Ezzedine al-Qassam Brigades, Israel's military spokesman Rear Admiral Daniel Hagari said at the time.

But Hagari said then that it was unclear if Issa had been killed in the operation, adding: "We are still examining the results of the strike, and final confirmation has yet to be received."