By Gram Slattery and Humeyra Pamuk
UNITED NATIONS, Sept 22 (Reuters) - US President Donald Trump used his UN General Assembly speech on Tuesday to argue that the war with Iran prevented Tehran from obtaining a nuclear weapon and warn that he could "annihilate the Islamic Republic" if no deal is reached to end the conflict.
While predicting his administration would strike a peace deal with Iran following the November 3 US midterm elections, Trump called on other nations to join America in isolating Iran economically to force it to the negotiating table.
"I have a big decision to make. Will a deal be made with Iran that lets them rebuild and create a far greater country than it ever was before?" 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?"
Trump added: "Do I drive them into hell with no chance of survival and no hope of future greatness or generations? But I believe we'll make a deal right after the election."
The speech marked the latest justification Trump has offered for the war with Iran. He has previously cited a range of reasons for the February US-Israeli strikes, including Tehran's nuclear program, its support for regional proxy groups and the prospect of regime change.
Iran has consistently denied seeking to develop nuclear weapons.
Outside the UN headquarters, dozens of anti-Iranian government demonstrators gathered, a few of them holding up signs calling for freedom and democracy and decrying dictatorship.
"I believe we'll make a deal right after the election because it doesn't make sense for them not to. They're waiting to see how I do in the midterm election," Trump said during a speech to the United Nations General Assembly.
In addition to defending the decision to attack Iran, Trump was expected to use his speech to criticize the UN, highlighting his administration's efforts to prevent the organization and other international bodies from encroaching on US sovereignty or advancing what it views as a left-wing agenda, according to a White House official who spoke on condition of anonymity.
Trump last year caused a stir with a combative speech at the UN, saying that other countries were "going to hell" for, among other things, climate policy and mass migration.
The speech kicked off a day of high-level diplomacy at the United Nations, where Trump was due to meet more than a dozen world leaders as wars in the Middle East and Ukraine continued to test his foreign policy agenda.
After his speech, Trump is scheduled to meet with no fewer than 11 world leaders, bilaterally or in group settings.
Later on Tuesday, Trump will meet with British Prime Minister Andy Burnham, Ukrainian President Volodymyr Zelenskiy, Venezuela's interim leader Delcy Rodriguez, Danish Prime Minister Mette Frederiksen, Greenland Prime Minister Jens-Frederik Nielsen, and the representatives of the Gulf states of the United Arab Emirates, Saudi Arabia, Oman, Bahrain, Kuwait and Qatar.
In the evening, he may meet dozens more leaders, albeit briefly, during a leaders' reception. Trump met with French President Emmanuel Macron on Monday. Additions to his Tuesday schedule are possible.
The long list of foreign leader meetings reflects the US president's focus on foreign affairs during his second term, during which he has started multiple wars, questioned longstanding alliances, threatened allies with invasion and sought to broker well over a dozen conflicts, with mixed success.
The US-Israeli war against Iran has been particularly consequential, driving up fuel prices globally, dragging down Trump's approval ratings and presenting a challenge for Republicans running in the November 3 congressional midterm election. On Monday, a Reuters/Ipsos poll showed Trump's approval rating falling to an all-time low of 32%, as his fellow Republicans soured on his handling of the cost of living.
Among the closely watched meetings will be the seven-way gathering with the Gulf leaders, many of whom are alarmed by the recent advances of the Houthis, Iran-backed militants who have captured wide swathes of Yemen, attacked US ally Saudi Arabia and threatened shipping through the strategic Bab el-Mandab Strait.
Political allies and opponents will also be closely watching Trump's first-ever meeting with Venezuela's Rodriguez, who rose to power with the Trump administration's blessing after US forces snatched President Nicolas Maduro in January and took him to New York to face drug trafficking charges.
Trump's allies say the US is working with Rodriguez to open Venezuela's oil sector to US investment, but Democrats and some Republicans say his administration has not done enough to press for new elections in the South American nation.
During the meeting with the leaders of Denmark and Greenland, its overseas territory, Trump will ink an accord designed to increase US military presence on the island while limiting that of geopolitical adversaries. Danish and Greenland officials hope the accord will put an end to Trump's past comments suggesting he might take Greenland by force.
(Reporting by Gram Slattery and Humeyra Pamuk; Editing by Don Durfee and Howard Goller)
