Living conditions for Palestinians in Gaza have reached breaking point, a senior UN official has said.
More that 220 Palestinians have been killed in Gaza since the end of June
The warning came from Karen Abuzayd, head of the UN Relief and Works Agency.
She said Israeli military action in Gaza over recent weeks was creating suffering and mass despair, rather than any desire for political compromise.
Israel keeps Gaza's borders largely sealed and conducts regular military operations, prompted in part by the capture of an Israeli soldier.
Ms Abuzayd said that Gaza was becoming increasingly isolated by financial sanctions, the Israeli siege of the territory and daily targeted killings.
"It would be great to have an international presence, civilian, military, whatever," she said, adding that an international force of peacekeepers could offer Gaza's 1.5m people some protection.
"The strangulation of commerce and trade has ruined the economy, it has brought the institutions of government to a point of near-meltdown and badly shaken the society," she said.
"These pressures and tactics have not resulted in a desire for compromise on the part of the government or the people, or yet the fall of the government, but rather have created mass despair, anger and a sense of hopelessness and abandonment."
Ms Abuzayd suggested foreign monitors may be able to help some of Gaza's border crossings re-open more frequently, enabling goods and people to move freely.
She said EU monitors had successfully enabled Gaza's Egyptian border crossing at Rafah to function until its closure by Israel earlier this summer.
"It allowed people to move," she said.
"It was very exciting for people who'd been under occupation for 37 years to finally get out of their country."
An Israeli spokeswoman quoted by the Associated Press news agency said the international community must urge Palestinians "to stop terror and to recognize Israel".
Ms Abuzayd also criticised a temporary mechanism set up to deliver aid to the Palestinians as a "stopgap measure" that had not improved Gaza's "appallingly low standards of living".
Foreign aid donors established the mechanism in May to deliver limited funds for Palestinian public services.
Donations to the Palestinian Authority were suspended over the recently-elected Hamas government's refusal to recognise Israel and renounce violence.
In late June, Israeli Cpl Gilad Shalit was captured in a cross border raid by Palestinian militants.
Between then and the end of August, Israeli security forces killed 226 Palestinians, 54 of them minors, in the Gaza Strip, the Israeli Human rights group, B'Tselem has reported.
The group says 114 of these were not taking part in any hostilities when killed, and 46 of them were minors.
In August alone 76 Palestinians were killed by the Israeli military, 19 of them minors, in the West Bank and Gaza Strip. More than half of those killed were not participating in hostilities at the time, B'Tselem says.