A lack of accountability for the killing of United Nations staff and humanitarian aid workers in the Gaza Strip is “totally unacceptable,” UN Secretary-General Antonio Guterres told Reuters in a wide-ranging interview on Wednesday.

Guterres also said that establishing a UN peacekeeping force would not be the “best solution” for Haiti, where armed gangs have taken over much of the capital and expanded to surrounding areas, fueling a humanitarian crisis with mass displacements, sexual violence and widespread hunger.

Ahead of the annual meeting of world leaders at the UN General Assembly later this month, Guterres summed up the past year as “very tough, very difficult.”

It has been dominated by the war in Gaza, which began just two weeks after leaders left New York following last year’s assembly when Palestinian Hamas militants killed 1,200 people and took about 250 hostages in a cross-border rampage into Israel, according to Israeli tallies.

Describing Israel’s retaliation against Hamas in Gaza - where local health officials say some 41,000 Palestinians have been killed since the war began - Guterres said there have been “very dramatic violations of the international humanitarian law and the total absence of an effective protection of civilians.”

“What’s happening in Gaza is totally unacceptable,” he said.

The Israeli military says it takes steps to reduce the risk of harm to civilians and that at least a third of the Palestinian fatalities in Gaza are militants. It accuses Hamas of using Palestinian civilians as human shields, which Hamas denies.

Nearly 300 humanitarian aid workers, more than two-thirds of them UN staff, have also been killed during the conflict, according to the UN Guterres said there should be an effective investigation and accountability for their deaths.

“We have courts, but we see that the decisions of courts are not respected, and it is this kind of limbo of accountability that is totally unacceptable and that also requires a serious a serious reflection,” Guterres said.

The top UN court - the International Court of Justice - said in July that Israel’s occupation of Palestinian territories and settlements is illegal and should be withdrawn. The 193-member UN General Assembly is likely to vote next week on a draft resolution that would give Israel a six-month deadline to do so.

Guterres said he has not spoken with Israeli Prime Minister Benjamin Netanyahu - who has long accused the UN of being anti-Israel - since the deadly Hamas attack in Israel on October 7 last year. The pair met in person at the UN a year ago and Guterres said he would do so again - if Netanyahu asked.

“I have not talked to him because he didn’t pick up my phone calls, but I have no reason not to speak with him,” Guterres said. “So if he comes to New York and he asks to see me, I will be very glad to see him.”

When asked if Netanyahu planned to meet with Guterres on the sidelines of the UN General Assembly, Israel’s UN Ambassador Danny Danon said that Netanyahu’s schedule hasn’t been finalised yet.