Trump threatens to 'annihilate' Iran in bombastic UN speech

US President Donald Trump said Tuesday he has to decide whether to make a deal with Iran or "annihilate" the country, in a bombastic speech to the United Nations that appeared tailored to war-weary American voters.

The 80-year-old president's threat came amid repeated boasts that under him the United States is successfully confronting its adversaries and reshaping the world order to its own advantage.

"While others have spoken of peace, I have made peace. While others have ignored threats, I have confronted them," Trump told the room full of world leaders at the UN General Assembly in New York.

Despite claiming credit as a peacemaker, Trump delivered a jarring warning as he sought to justify the nearly seven-month war against Iran, which he said was launched to stop Tehran acquiring nuclear weapons.

"I have a big decision to make -- will a deal be made with Iran that lets them rebuild and create a far greater country?" Trump said.

"Or do I annihilate the Islamic Republic and do it quickly, never giving them a chance to kill and destroy people and countries again? Do I drive them into hell with no chance of survival?"

Trump reiterated that he believed Iran would "make a deal right after" the US midterm elections in November -- in which his Republican party faces losing control of Congress, at least partly due to high fuel prices caused by the unpopular war.

Much of the rest of his speech was dedicated to proclaiming his own achievements in making the United States the "most powerful country in the world."

Trump threatened to use the "unmatched military might" of the US to secure Washington's interests in Latin America, and said the Communist-run island of Cuba would soon "fall".

He also hailed a deal with Greenland under which he said Washington would build two bases in the Arctic territory. Trump was signing the deal with the leaders of Denmark and Greenland on the sidelines of the UN.

The Greenland deal has sparked bitter divisions within long-term US alliances including NATO and revived fears that under Trump Washington is no longer a reliable partner.

The volatile US president also renewed his attack on what he said were "globalist" bodies, including the United Nations itself and the International Criminal Court, which he urged other countries to boycott.

Trump's 37-minute speech to the world body was perhaps less fiery than last year's, which was characterized by Trump's extraordinary accusations of UN sabotage.

Those claims were sparked when an escalator in New York briefly stopped working and the teleprompter glitched. This year Trump ascended the escalator with wife Melania without a hitch, and appeared to read his speech faithfully from the teleprompter.

Trump has regularly attacked the UN and its outgoing leader Antonio Guterres since returning to office.

Guterres kicked off the week of speeches by warning of the "specter of ethnic cleansing" in Israel's settlements expansion in the occupied West Bank.

He also called for US-Chinese dialogue on the future of AI and singled out global energy companies for treating the atmosphere "as an open sewer."

Just before Trump was Brazilian President Lula Inacio Lula da Silva, whose country by tradition is always first to speak at the annual gathering of leaders.

Trump, who has supported Lula's opponents and other right-wing candidates across Latin America, may have not liked what he heard.

Leftist Lula, running for reelection, said that Brazil did not fit in anyone's "backyard" -- a statement at odds with Trump's claims to rule the roost across the Americas.

As well as his closely watched speech to the General Assembly, Trump was holding side meetings with Britain's new prime minister, Andy Burnham, Ukrainian President Volodymyr Zelensky and Japanese premier Sanae Takaichi.

Trump was also set to hold his first meeting with Venezuela's interim leader Delcy Rodriguez. Rodriguez has governed under intense American pressure since US forces captured her predecessor Nicolas Maduro in January.