When President Donald Trump is on the speaker's roster, the audience can be pretty sure it will get a solid dose of his famous rhetoric and manner regardless of the location and the nature of the address.

And Trump's much anticipated maiden speech at the United Nations General Assembly in New York did not disappoint. The president delivered several lines of what can only be described as typical "Trumpisms."

The one that will likely be quoted most is calling North Korea's leader "rocket man," as he had done previously in one of his Twitter tirades. He further asserted that Kim Jong Un was on a "suicide mission." Trump also threatened to "totally destroy" North Korea if it continued with its nuclear arms development.

In a manner not common for a US president, he went on to tell the assembled global leaders that some parts of the world "are going to hell."

"I have not heard a president referring to a foreign leader with a phrase like 'rocket man'," said Mary Stuckey, a presidential rhetoric scholar at Pennsylvania State University. This is concerning, she noted, especially since it was said in conjunction with a threat to annihilate North Korea at the main body devoted to international cooperation, the United Nations.

Out of place

"It was indecorous on Twitter and it is even more out of place in the UN General Assembly”, said Jennifer Mercieca, who studies presidential rhetoric at Texas A&M University.

What's more, noted Kathleen Hall Jamieson, director of the Annenberg Public Policy Center and a presidential rhetoric expert at the University of Pennsylvania, "the threat to 'totally destroy North Korea' if the US is 'forced to defend itself or its allies', is unartfully phrased because it suggests that the intent is obliterating a geographic space and by implication the innocent citizens within it who have no say in the decisions of Kim Jong Un."

And words can have consequences, argued Nicholas Miller, a nuclear proliferation scholar at Dartmouth College.

Destabilizing statements

"Trump's statements on North Korea and Iran are destabilizing and increase the odds of conflict and nuclear proliferation, said Miller. "Threatening to 'totally destroy North Korea' only makes it more likely that Pyongyang will feel that it must use its nuclear weapons early if it believes — rightly or wrongly — that war is imminent."

The location aside, Trump's bellicose remarks vis-a-vis North Korea are old hat and therefore unlikely to move the needle in the psychological game that is being played by the president and the North Korean leader.

But his statements on Iran could have a much greater impact, as they could indicate that the president may be prepared to nullify or change the nuclear deal reached with Tehran when it is up for a review in Washington next month.

"Trump's hint that he may withdraw from or otherwise undermine the JCPOA, [the Joint Comprehensive Plan of Action nuclear deal with Iran] is also concerning," said Miller.

"US withdrawal would increase the likelihood that Iran ramps up its enrichment program, bringing it very close to a nuclear weapons capability. This would increase the risk of war in the region, make it more likely that countries like Saudi Arabia seek nuclear weapons of their own, and make it even harder to find a diplomatic solution to the North Korea issue."

No invitation for debate

"He didn't invite debate or discussion, but did proclaim that the UN had not heard the last on the Iran deal," said Mercieca, adding that this kind of behavior is unusual for a forum like the United Nations General Assembly, which is a deliberative body.

Probably to the relief of many present in New York, Trump did not specifically address previous plans to massively cut US funding for the UN. Instead, he appeared to imply a carrot-and-stick approach with the organization. While he complained about the "unfair" burden Washington, as the UN's biggest financial contributor, shouldered, he said it could be all worth it, if the UN fulfilled its role.

But on this issue, as on many others like North Korea, Iran or the ongoing crisis in Venezuela which he cited, Trump did not offer any concrete policy suggestions or demands.

What does Trump want from the UN?

"You usually get an indication of what the president wants the UN to do," said Stuckey. "And that was absent."

Instead, Trump tried to square the "America First" slogan that has characterized his presidency with the goal of cooperation among the international community that the UN represents.

"He attempted to fold his American First policies into a version of enlightened self-interest for all nations and invited UN member nations to also put their nation and their citizens first," said Mercieca.

Happy base

Judging from the reaction of the audience present for Trump's speech, his repeated call for "strong, sovereign nations" as the pillar of the UN's work was a hard sell for the president. The response to this, as to most of Trump's remarks, was silence, or a few times, polite applause.

While the foreign leaders assembled in New York may not appreciate what they heard from Trump's UN debut, many of his American supporters will probably be happy with the performance of their president who — in front of the global political elite — defended "America First."

"I think it is a speech that will very much please his base," said Stuckey.