A top Hamas official said on Wednesday that "intensifying" Israeli military operations in the Gaza Strip would harden the Palestinian group's negotiating position in mediation efforts towards a truce.
In recent days, Israeli forces have increased raids in northern Gaza as heavy fighting again raged in the far-southern city of Rafah.
And across the besieged territory, deadly strikes have hit four schools used as shelters, sparking rebuke from France and Germany which both labelled the attacks "unacceptable".
Hamas official Hossam Badran, asked about the increased military operations, told AFP that Israel "is trying to pressure negotiations by intensifying bombing operations, displacement, and committing massacres".
As long-stalled diplomatic efforts have gathered pace, aiming for a hostage release deal and Gaza truce after more than nine months of devastating war, Badran said Israel was trying to force Hamas's hands.
According to Badran, the Israeli government was "hoping that the resistance will relinquish its legitimate demands", which include a complete ceasefire and full withdrawal of Israeli troops from Gaza.
But "the continuation of massacres compels us to adhere to our demands", he said.
On Sunday, a Hamas official told AFP on condition of anonymity that the group was ready to discuss a hostage release deal with Israel even without a "complete" ceasefire.
But now, Badran said, "we cannot determine to what extent the negotiations can proceed despite the flexibility we have shown."
Truce negotiations, mediated by Qatar and Egypt with US support, are due to resume in Doha on Wednesday.
Hamas's political leader, Ismail Haniyeh, warned Monday that Israel's latest offensive in Gaza City and Rafah risked sending back "the negotiating process to square one".
The war began with Hamas's October 7 attack on southern Israel that resulted in the deaths of 1,195 people, mostly civilians, according to an AFP tally based on Israeli figures.
The militants also seized 251 hostages, 116 of whom remain in Gaza, including 42 the military says are dead.
Israel responded with a military offensive that has killed at least 38,295 people in Gaza, also mostly civilians, according to figures from the Hamas-run territory's health ministry.