Only around 30 to 35 percent of Hamas fighters have been killed after more than seven months of operations by Israel in the Gaza Strip, US intelligence sources told Politico.
According to Politico, the majority of fighters who were members of the Palestinian movement prior to the 7 October attack in southern Israel are still alive, even as the reported death toll in Gaza has reached over 35,000 dead, mostly women and children.
In addition, around 65 percent of Hamas' tunnel infrastructure remains intact, Politico's sources said, and thousands of new members are said to have been recruited to the group in recent months.
The report comes as Washington has become increasingly concerned about the viability of Israel's stated aim of destroying the Palestinian group.
On Monday, General Charles Brown, chair of the joint chiefs of staff, criticized Israel's strategy in Gaza, warning that the failure of Israeli forces to both secure captured territory and eliminate Hamas from northern Gaza was hampering its ability to achieve its military objectives.
The comments by Brown were a rare note of criticism from the US military, which has aided Israel in its war on Gaza by providing military equipment and assistance through intelligence sharing.
That cooperation has polarized President Joe Biden's Democratic political base in an election year.
While the Biden administration has thrown its full-fledged support behind Israel's war efforts, some officials in the administration are beginning to offer more criticism of the Israeli government, particularly on its war strategy and the overall aid situation for the Palestinians in Gaza.
Around 128 people taken captive by Hamas and other Palestinian groups remain in Gaza. Israel's government insists that military pressure is the best way to free them, and says it will not end its war in Gaza until it "eliminates" Hamas. Dozens of the captives are believed to be dead.
There is growing discontent in Israel over the war's progress, with Israeli Prime Minister Benjamin Netanyahu accused of giving up on the Israeli captives.