Bloomberg - French President Emmanuel Macron used his inaugural appearance at the United Nations General Assembly to offer an almost a point-by-point rebuke to another first-timer: U.S. President�Donald Trump, who spoke two hours earlier.

Macron insisted the world�s challenges were best met by working together, not alone, and he ruled out any renegotiation of the�Paris climate accord, saying the rest of the world will go ahead with or without the U.S. He warned that Trump�s threats to exit the�Iran nuclear accord�would make the world more dangerous, and said brandishing military threats against North Korea was �impetuous� and counter-productive.

�Our challenges are global, and more than ever we need multilateralism,� Macron said during his 35-minute address to the assembly.��Walls don�t protect us; what protects us is our joint willingness to change history. We are all linked.�

Earlier in the day, Trump ripped into the Iran accord and�warned�he�d destroy North Korea if they threatened the U.S., and he avoided any mention the Paris carbon emissions accord from which he�s begun�the formal process of withdrawal. The dueling speeches -- aides to Macron said he retouched his speech at the last moment to respond to Trump�s -- were the latest episode in a complicated relationship between the two men.

The two leaders have clashed on issues such as climate but seem to have developed a close working relationship, sealed during a friendly visit by Trump to France�s Bastille Day parade July 14 that so pleased Trump that he�s said he wants to replicate it in the U.S.

At a later news conference, Macron said that Trump respects leaders who make their differences clear. He said he shares many views with Trump, and that their countries work closely on security and terrorism, but won�t hold back on areas where he thinks the U.S. president was wrong.

Macron said in his speech that questioning the Iran nuclear accord �without proposing anything to replace it is a grave error.� He went on to ask: "If we denounce the accord, do we better manage nuclear proliferation? I don�t think so.�

Trump, who today called the Iran nuclear accord �one of the worst ever,� faces an Oct. 15 deadline to inform Congress whether the U.S. will continue to certify Iran�s compliance. The�International Atomic Energy Agency�has�found�Iran to be meeting its responsibilities under the 2015 accord, which capped the country�s nuclear program in exchange for sanctions relief.

On North Korea, Macron said �you only need to look at the map� to see why there isn�t a military solution to North Korea�s nuclear tests. �We are in a geography where a military intervention would be very complex, an area that is densely populated,� he said at his news conference.

Special �Debt�

In an interview that ran on CNN as he was giving his news conference in New York, Macron said he �regrets� Trump�s choice to leave the Paris climate treaty and said that he wants �to convince him to come back to this agreement because, for me, that�s the core agreement for climate.� But he ruled out any weakening of the treaty.

While Trump began his speech by touting the strength of the U.S. economy and saying countries should look out for their own interests, Macron began his by saying France had a special �debt� to the UN because of its birth in the ashes of the Second World War.

�If I am here it�s because of countries 70 years ago that rose up to defeat the barbarism that had occupied my country,� he said. �I owe it to those who, once the war was over, chose reconciliation and reconstruction, to those who thought it was necessary to resurrect the ideas that had been so violated in the war.�