A ceasefire between Israel and Hamas held into a third day on Sunday as mediators spoke to all sides about extending the period of calm after the worst outbreak of fighting in years.
Egyptian mediators have been shuttling between Israel and the Gaza Strip, which is ruled by Hamas, to try to sustain the ceasefire and have also met the Islamist group's rival, Palestinian President Mahmoud Abbas, in the occupied West Bank.
Lynn Hastings, the United Nations Humanitarian Coordinator for the Palestinian territories, said on Sunday the UN would launch an appeal to repair the damage in densely populated Gaza, where there is a threat of COVID-19 spreading.
"The escalation has exacerbated an already dire humanitarian situation in Gaza, generated by nearly 14 years of blockade and internal political divisions, alongside recurrent hostilities," she said in a statement issued from the Palestinian enclave.
"We must also ensure support to continue addressing needs that already existed, including those arising from the ongoing pandemic,” Reuters quoted her as saying.
US President Joe Biden has said Washington will work with UN agencies on expediting humanitarian aid for Gaza "in a manner that does not permit Hamas to simply restock its military arsenal.”
Israel has blockaded Gaza since 2007, saying this prevents Hamas bringing in arms. Hastings said the United Nations had long been asking Israel to stop the blockade and would continue doing so.
Palestinian officials put reconstruction costs at tens of millions of dollars in Gaza, where medical officials said that 248 people were killed during the 11 days of fighting.
Medics said rocket fire and a guided missile attack killed 13 people in Israel during the hostilities.
Economists said Israel's recovery from the COVID-19 pandemic could be curbed by the hostilities. Israel reopened its borders to foreign tourists on Sunday but said it would take time to revive the tourism industry.
Israel has fully vaccinated about 55% of its population and COVID-19 cases have dropped sharply.