UNITED NATIONS — UN Secretary-General Antonio Guterres warned global leaders Tuesday of the looming risk of the world splitting in two, with the United States and China creating rival internets, currency, trade, financial rules “and their own zero-sum geopolitical and military strategies.”

In his annual “state of the world address” to the General Assembly’s gathering of heads of state and government, Guterres said the risk “may not yet be large, but it is real.”

“We must do everything possible to avert the great fracture and maintain a universal system, a universal economy with universal respect for international law; a multipolar world with strong multilateral institutions,” he told presidents, prime ministers, monarchs and ministers from the UN’s 193 member states.

Guterres painted a grim picture of a deeply divided and anxious planet facing a climate crisis, “the alarming possibility of armed conflict in the Gulf,” spreading terrorism, rising populism and “exploding” inequality.

His speech was followed by the traditional first speaker — Brazil, represented by its new president, Jair Bolsonaro — and the United States, represented by President Donald Trump.

British Prime Minister Boris Johnson, who is scheduled to speak later, said he was returning to London immediately afterward, where he will face the fallout of a court ruling against his decision to shut down Parliament during the debate amid the crucial countdown to the UK’s withdrawal from the European Union.

The United Nations, designed to promote a multilateral world, has struggled in the face of increasing unilateralism by the US and other nations that favor going it alone.

Trump stressed in his speech that “love of our nations makes the world better for all nations.”

“The future does not belong to globalists,” he said. “The future belongs to patriots.”

Not so, said France’s President Emmanuel Macron, who disagreed with the American president and said the world’s problems cannot be solved by turning inward.

True patriotism, Macron said, “combines a love of one’s nation” with a multilateralism “based on real cooperation that strives to produce concrete results.”

Said Guterres: “We are living in a world of disquiet.”

“A great many people fear getting trampled, thwarted, left behind. Machines take their jobs. Traffickers take their dignity. Demagogues take their rights. Warlords take their lives. Fossil fuels take their future,” he said.

Yet the secretary-general said people still believe in “the spirit and ideas” of the United Nations and its foundation of multilateralism, of all countries working together.

But he asked the VIP crowd in the horseshoe-shaped assembly chamber: “Do they believe leaders will put people first?”

“We, the leaders must deliver for we, the peoples,” Guterres said.

The global meeting unfolds against the backdrop of flaring tensions between Iran and Saudi Arabia, backed by its longtime ally, the United States. The Saudis say Iran was responsible for an attack earlier this month on two oil facilities in the kingdom, which Iran denies.

The Trump administration has been engaged in an escalating series of harsh words and threats with Tehran. The US has imposed increasingly crippling sanctions.

Iranian President Hassan Rouhani is scheduled to address world leaders Wednesday.

Guterres gave a dire warning about the situation in the Gulf.

“Above all, we are facing the alarming possibility of armed conflict in the Gulf, the consequences of which the world cannot afford,” he said. “In a context where a minor miscalculation can lead to a major confrontation, we must do everything possible to push for reason and restraint.”

Trump said the US “does not seek conflict with any other nation” and desires peace, but “I will never fail to defend America’s interests.”

He called Iran “the world’s No. 1 state sponsor of terrorism” and accused it of fueling wars in Syria and Yemen while squandering its wealth in a “fanatical quest” for nuclear weapons and the means to deliver them.

“No responsible government should subsidize Iran’s bloodlust,” Trump said, warning that as long as Iran’s “menacing behavior” continues, US sanctions will be tightened.

Guterres also warned that “outside interference” is making peace processes more difficult. And he pointed to unresolved conflicts from Yemen to Libya, Afghanistan and beyond.

“A succession of unilateral actions threatens to torpedo a two-state solution between Israel and Palestine,” Guterres said. “In Venezuela, 4 million people have fled the country — one of the largest displacements in the world. Tensions are elevated in South Asia, where differences need to be addressed through dialogue.”

France’s Macron appealed to world leaders to bring back the “courage” to make peace, especially in the Middle East.

He urged the United States, Iran and countries in the region to resume negotiations and the target should be that Iran never develop or acquire nuclear weapons, a solution to the conflict in Yemen, a regional security plan that includes securing navigation and finally the lifting of economic sanctions.

Tuesday’s opening session of the so-called General Debate followed three days of meetings focusing on the growing environmental threat to the planet.

Guterres told leaders “what once was called ‘climate change’ is now truly a ‘climate crisis’ and what was once called ‘global warming’ has more accurately become ‘global heating.’”

While satellite data from the Brazilian Space Agency has shown a sharp increase in deforestation and forest fires in the past year, Bolsonaro told leaders: “The Amazon is not being devastated nor is it being consumed by fire as the media misleadingly says.”

This year’s General Assembly session, which ends Sept. 30, has attracted world leaders from 136 of the 193 UN member nations, according to figures it released Friday. That large turnout reflects a growing global focus on addressing climate change and the perilous state of peace and security.

Other countries will be represented by ministers and vice presidents — except Afghanistan, whose leaders are in a hotly contested presidential campaign ahead of Sept. 28 elections, and North Korea, which downgraded its representation from a minister to, likely, its UN ambassador. Saudi Arabian Crown Prince Mohammad bin Salman and Israeli Prime Minister Benjamin Netanyahu canceled plans to attend and are sending ministers.