The new United Nations Secretary General insisted Israel must be treated like any other state at the world body as he delivered the first ever address by an occupant of his office to a gathering of international Jewish leaders.

Antonio Guterres also vowed that he would be on the frontline in the fight against anti-Semitism as he kicked off the World Jewish Congress’s plenary in New York, attended by leaders from 90 countries.

Addressing claims of bias against Israel at the UN, the former Portuguese prime minister described the dynamics of its bodies as complex and said it was not the role of a Secretary General to dictate the positions of member states. “But the state of Israel needs to be treated like any other state,” he added, saying he’d already had cause to intervene to enforce this.

It came just three weeks after the UN Economic and Social Commission for Western Asia removed a report accusing Israel of apartheid, under pressure from Guterres. The Commission’s chief resigned over the matter.

Referring to Simon Schama’s The Story of the Jews, he recalled the persecution faced by the community through the years and branded the expulsion of Jews from Portugal in the 15th century as “the most stupid mistake in the country’s history”. The Holocaust, the most “evil crime against humanity”, was the culmination of millennia of persecution.

United Nations Human Rights Council

United Nations Human Rights Council

Rather than having ended with the Shoah, anti-Semitism is “alive and well” with murders, desecrations and online hate speech. “As Secretary General I will be on the frontline in the fight against anti-Semitism.

He pointed out that a modern form of anti-Semitism “is the denial of the right of the state of Israel to exist” – stressing this was entirely different from disagreeing with the policies of a government.

He told the 600-strong audience: “I was always convinced the solution is the two state solution and I’ll do everything I can to support it. But I will never allow the legitimate positions that might exist critical of Israel or the Palestinians to undermine the right of Israel to exist and the right of Israel to find peace and security.”

He also hailed the “extraordinary contribution” of Jews to civilisation. “The world would not be the same without Einstein. The world would not be the same without Freud.”