United Nations Secretary-General Antonio Guterres is warning that impunity, inequality and uncertainty are creating an “unsustainable world” where a growing number of countries believe they should have a “get out of jail free” card.

“We can’t go on like this,” he said.

Mr Guterres was speaking as the General Assembly’s annual debate among presidents, prime ministers, monarchs and other leaders began on Tuesday.

Citing deepening geopolitical divisions, wars with no end in sight, climate change and nuclear and emerging weapons, he said humanity is “edging towards the unimaginable – a powder keg that risks engulfing the world”.

But, he says, “the challenges we face are solvable” if the international community confronts the uncertainty of unmanaged risks, the inequality that underlies injustices and grievances and the impunity that undermines international law and the UN’s founding principles.

“Today, a growing number of governments and others feel entitled to a ‘get out of jail free’ card,” he said in a reference to the classic board game Monopoly.

The world leaders’ meeting opened under the shadow of increasing global divisions, major wars in Gaza, Ukraine and Sudan and the threat of an even larger conflict in the wider Middle East.

Mr Guterres previewed his opening speech at Sunday’s Summit Of The Future, where he pointed to conflicts from the Middle East to Ukraine and Sudan and to the global security system, which he said is “threatened by geopolitical divides, nuclear posturing, and the development of new weapons and theatres of war”.

He also cited huge inequalities, the lack of an effective global system to respond to emerging and even existential threats, and the devastating impact of climate change.