In his final UN address, Guterres warns the world's 'fault lines' are widening into canyons

Four tests of power

António Guterres stood before the United Nations General Assembly on Monday for the last time as secretary-general and told the chamber, bluntly, that the institution he has led for a decade is running out of runway. "The fault lines in our world are widening," he said. "Cracks have become canyons."

The speech opened the general debate of the 81st session of the General Assembly, the annual gathering of world leaders in New York that runs through the week under the theme "Restoring trust, managing transformation: a United Nations that delivers for all." It was, by design and by circumstance, a valedictory address. Guterres's second five-year term ends on December 31, and a selection process for his successor is already under way, though no candidate has yet secured the backing needed to be recommended to the Assembly.

Guterres organized his remarks around four defining "tests of power," in his words: whether nations resolve conflicts through war or peace, whether economic gains are shared or hoarded, whether climate change is confronted or deferred, and whether artificial intelligence is governed or left to develop unchecked. According to the official U.N. summary of the session, he told delegates that "the power of law must prevail over the law of power" — a line that became the headline of the United Nations' own account of the day. Nearly 130 heads of state and government are expected to address the Assembly across this year's general debate. The session opened days after Guterres's outgoing predecessor as Assembly president, Germany's Annalena Baerbock, handed the presidency's ceremonial gavel to Bangladesh's Khalilur Rahman, who will preside over the 81st session through September 2027.

"The fault lines in our world are widening. Cracks have become canyons." — António Guterres, addressing the General Assembly, September 22, 2026

A blunt appeal on security, AI and climate

On security, Guterres said military strength alone cannot secure peace and pressed the world's major powers to recognize that "their power isn't so super," according to a Reuters dispatch carried by Business Day. He appealed for a "world built on interdependence," pointing to active wars in Gaza, Ukraine, Sudan, the Democratic Republic of Congo and Myanmar, and called for "a clear message from this hall: the fighting must stop" in the Middle East.

On artificial intelligence, he warned that "life-and-death decisions must never be surrendered to machines," and pushed for binding international guardrails rather than a patchwork of national rules, a position that lands as the U.N.'s own AI advisory body works to shape global governance recommendations. On climate, he repeated a demand he has pressed with increasing force in recent years: "Those who polluted the most — and profited the most — must do far more to repair the damage they caused. Polluters must pay." He called for redirecting revenue from fossil-fuel producers toward countries suffering climate-driven loss and damage. Guterres has held the secretary-general's post since January 2017 and departs after two full five-year terms, with the selection of his replacement still unresolved as leaders convened.

Reaction split along familiar lines

The tone of the day illustrated the divisions Guterres was describing. Assembly President Khalilur Rahman told delegates that "outside these walls, people are asking whether it works," and said that on Security Council reform, Africa wants to be "at the table, not on the menu," adding that "trust is not given — it is earned." Guterres closed his own remarks on a personal note: "So, on January 1st, when I am no longer secretary-general, be sure of this. Wherever I will be, whatever I will be doing, I will keep championing the conviction that peace is possible. I will continue to stand up for the values of the United Nations Charter and I will never, ever give up." Delegates gave him a standing ovation, according to coverage of the session.

Later the same day, President Trump addressed the Assembly with a starkly different framing, saying "while others have promised strength, I have used it to make America the most powerful country in the world," and criticizing the United Nations for what he described as imposing "the far-left agenda of globalist bureaucrats." The juxtaposition underscored the gap Guterres spent much of his address describing: between institutions built for collective action and major powers increasingly skeptical of the value of that cooperation.

Who is affected, and what happens next

The immediate audience for Guterres's warning is the roughly 130 world leaders and their delegations who will keep addressing the Assembly through the rest of the week, but the substance of his appeal reaches further: countries seeking Security Council reform and a greater voice for Africa; nations bearing the costs of climate change with the least responsibility for causing it; governments and companies racing ahead on AI deployment without agreed international rules; and populations in Gaza, Ukraine, Sudan, Congo and Myanmar whose conflicts he cited as evidence that cease-fires too often amount to little more than pauses in violence.

For the United Nations itself, the practical next step is the selection of Guterres's successor, a process member states are expected to advance during this General Assembly session even as the general debate continues. Guterres remains in office through the end of the year, and U.N. officials have said he intends to use the remaining months to keep pressing the same agenda — climate finance, AI governance and institutional reform — that dominated Monday's speech, according to the United Nations' own news service.