Iran’s envoy to the United Nations has said that Israel's killing of scores of Palestinian protesters on May 14 was a pre-planned measure.

Gholamali Khoshroo made the remarks on Tuesday while addressing the UN Security Council Open Debate on the Protection of Civilians in Armed Conflict.

He added the Israel committed the crime with complete impunity granted to it by Washington.

"The Israeli army committed yet another war crime in Gaza, killing more than 60 and injuring thousands more unarmed Palestinian civilians in a single day. Given the circumstances, there is no doubt that these vicious attacks and killings were planned and deliberate," he said.

"These criminal acts took place with total impunity extended to the Israeli regime by the United States in this Council, the same country that later tried to prevent the appointment of a Commission of Inquiry in the Human Rights Council," he added.

Khoshroo added the US later attempted to shield Israel by blocking the Human Rights Council from appointing a commission aimed at probing its actions.

Israeli forces killed at least 62 Palestinians during protests near the Gaza fence on the eve of the 70th anniversary of the Nakba Day (Day of Catastrophe), which coincided with Washington’s embassy relocation from Tel Aviv to occupied Jerusalem al-Quds.

More than 2,700 Palestinians were also wounded as the Israeli forces used snipers, airstrikes, tank fire and tear gas to target the demonstrators.

UN warns of deteriorating health system in the Gaza Strip

Meanwhile, the UN agency for Palestinian refugees (UNRWA) has warned that the Tel Aviv regime's violent crackdown on protests has brought Gaza’s healthcare system to a breaking point.

"This morning I'm sending out an emergency call to help save Gaza's health system," UNRWA Commissioner-General Pierre Krahenbuhl.

He went on to also call for boosting UNRWA's ability to provide care to the released patients and the many amputees that will require long-term assistance.