U.N. Secretary-General Antonio Guterres gave his last speech to world leaders on Tuesday.

He called for "a world built on interdependence."

He said wars, rising temperatures and artificial intelligence are making the world more divided.

He asked leaders not to let the future move toward division, deal-making and mistrust.

Guterres leaves his job at the end of this year.

This made his message more urgent.

He also told powerful countries that their power "isn't so super."

He said military power alone cannot keep peace.

About an hour later, U.S. President Donald Trump gave a different view of power.

He said he used strength to make America the most powerful country in the world.

Trump said the U.N. has "great potential."

But he criticized it for pushing what he called a far-left globalist agenda.

He also criticized groups like the International Criminal Court.

The U.S. does not belong to this court.

The meeting will focus on wars in Iran, Gaza, Ukraine, Sudan, Congo and Myanmar.

Leaders will talk about whether they can end these wars.

They will also talk about global warming, growing inequality and economic problems.

These problems come from blocked shipping routes and supply chains.

The future of the U.N. itself is also on the agenda.

This includes reform of the Security Council.

Guterres' second five-year term ends Dec. 31.

No clear successor has appeared.

He promised to "never, ever give up" on the values the U.N. stands for.

He left the stage to a long standing applause.

About 130 heads of state and government are expected to speak.

Trump and French President Emmanuel Macron spoke Tuesday.

Ukraine's Volodymyr Zelenskyy and Iran's Masoud Pezeshkian speak Wednesday.

Israeli Prime Minister Benjamin Netanyahu speaks to the assembly Thursday.

Palestinian President Mahmoud Abbas will not come because the U.S. refused him a visa.

But he will speak by video the same day.

China's Xi Jinping, Russia's Vladimir Putin and India's Narendra Modi are skipping the meeting.

France's U.N. ambassador, Jerome Bonnafont, said it is "extremely critical" for leaders to support the U.N.

He said it is a place for cooperation and dialogue, not confrontation.