The head of the United Nations warned gathered leaders Tuesday that impunity, inequality and uncertainty are driving modern civilization toward "a powder keg that risks engulfing the world" - the latest clarion call from Antonio Guterres that the global situation is becoming intolerable and unsustainable.

"We can't go on like this," the secretary-general said in an alarming state-of-the-world address as he opened the annual high-level gathering of the U.N.'s 193 member nations.

He said the world is in "an era of epic transformation" and facing challenges never seen before, with geopolitical divisions deepening, the planet heating and wars raging in the Middle East, Ukraine, Sudan and elsewhere with no clue how they will end.

"We are edging towards the unimaginable - a powder keg that risks engulfing the world," Guterres told presidents, prime ministers and ministers in the vast General Assembly hall.

But he stopped short of saying hope was gone. "The challenges we face," he said, "are solvable."

It's not an easy time in the world

Guterres wasn't the only one worried about the state of the world.

"I cannot recall a time of greater peril than this," said King Abdullah II of Jordan.

Guterres called the situation in Gaza "a nonstop nightmare that threatens to take the entire region with it." He said escalating air attacks across the Israel-Lebanon border have put Lebanon "at the brink." In Ukraine, he said, there is no sign of an end to the war that followed Russia's February 2022 invasion. In Sudan, he said, "a brutal power struggle has unleashed horrific violence," including widespread rape, and a "humanitarian catastrophe is unfolding as famine spreads."

The U.N. chief also pointed to "appalling levels of violence and human suffering" from Myanmar and Congo to Haiti, Yemen and beyond, and the expanding terrorist threat in Africa's Sahel region. He said the Summit of the Future that preceded Tuesday's start of the assembly's nearly weeklong "General Debate," was a first step. "But we have a long way to go."

At the two-day summit, the world's nations adopted a "Pact for the Future." It's a blueprint for starting to address challenges from tackling climate change and poverty to putting guardrails on artificial intelligence. It also speaks to reforming the United Nations, and other global institutions established after World War II, to suit the needs and threats in the 21st-century world.

The UN leader blames 'impunity'

Guterres said meeting the challenges of a world "in a whirlwind" requires confronting the three drivers of "unsustainability" - the uncertainty of unmanaged risks, the inequality that underlies injustices and grievances and the impunity that undermines international law and the U.N.'s founding principles.

"A growing number of governments and others feel entitled to a 'get out of jail free' card," he said - a reference to the classic board game Monopoly.

In his final speech before fellow leaders, President Joe Biden said he recognized the challenges of Gaza, Ukraine, Sudan and other global hotspots, but he remains hopeful.

"There will always be forces that pull our countries apart ... a desire to retreat from the world and go it alone," he said. "Our task is to make sure that the forces holding us together are stronger than the forces pulling us apart."

Brazilian President Luiz Inácio Lula da Silva, whose country speaks first in a tradition dating to the early years of the U.N., criticized Israel's attacks in Gaza and Lebanon.

"The right to self-defense became a right for vengeance, which prevents a deal for the release of hostages and delays a cease-fire," he said.

Lula decried the growth in global military spending for a ninth consecutive year to more than $2.4 trillion. "Those resources could have been used to fight hunger and deal with climate changes," he said.

Iran's new president, Masoud Pezeshkian - who had accused Israel on Monday of seeking a wider war in the Middle East - laid into Israel in his speech to the assembly Tuesday. He said its attacks in Lebanon in recent days "cannot go unanswered."

Leaders embroiled in conflicts will speak

At last year's U.N. global gathering, Ukraine and its president, Volodymyr Zelenskyy, took center stage. But as the first anniversary of Hamas' deadly attack in southern Israel approaches on Oct. 7, the spotlight is certain to be on the ensuing war in Gaza and escalating violence across the Israeli-Lebanon border, which is now threatening to spread to the wider Middle East.

Zelenskky was in the spotlight Tuesday afternoon at a Security Council meeting on Ukraine on the sidelines of the gathering, and he will be center stage again when he addresses world leaders in the assembly hall on Wednesday morning.

At the high-level council meeting, the Ukrainian leader dismissed the notion of peace talks with Moscow, calling instead for unspecified global "action" to force Russia into peace for invading his country and to comply with the U.N. Charter's requirement that every country respect the sovereignty and territorial integrity of all other nations. Russia's U.N. Ambassador Vassily Nebenzia accused Slovenia, which holds the council's rotating presidency this month, of giving Zelenskyy a platform "to malign the Russian Federation."

Palestinian President Mahmoud Abbas is scheduled to speak Thursday morning and Israel's Prime Minister Benjamin Netanyahu on Friday.

On another hot spot, the Security Council scheduled an emergency meeting late Wednesday on the escalating violence in Lebanon at the request of France.

From the Associated Press