In last month's deadly flare-up, Palestinian militants fired more than 700 rockets into Israel, killing four Israeli civilians, the first Israeli fatalities from rocket fire since the 50-day war in 2014, known in Israel as Operation Protective Edge.
Ismail Haniyeh told foreign reporters in Gaza on Thursday that the understandings, brokered by Egypt, Qatar and the U.N., are now hanging in the balance.
He said Israel has shown "no respect" for the terms and the 2 million residents of Gaza who "have not felt" any improvement to their living conditions.
Israel acknowledges no formal arrangements.
In the meantime, Qatari envoy to the Strip, Mohammed al-Emadi, said 60,000 Gazan families in need will begin receiving stipends of $100 each sometime on Thursday.
The announcement comes after Israel allowed Qatari delegation to deliver $15 million in relief funds for the coastal enclave’s residents.
Of the funds transferred to Gaza, $10 million will be allocated to the families, while the other $5 million will go to the UN-funded program "Cash for Work." Another $10 million was apparently transferred to Israel to fund the purchase of fuel for Gaza's power plant.