Threatening to "totally destroy" North Korea. Prophesying that some nations in the room are "going to Hell." Warning diplomats they "haven't heard the last of" his attacks against the Iran nuclear deal.

Beyond the dark picture of the world U.S. President Donald Trump painted from the podium at the United Nations General Assembly on Tuesday, world leaders in the room may have taken comfort in one word he pitched again and again.

Sovereignty.

Trump mentioned the concept 21 times in 40 minutes, making the case for national self-interest and the rights of countries to have their own world views and systems of government respected without outside meddling.

"Our success depends on a coalition of strong and independent nations that embrace their sovereignty, to promote security, prosperity and peace, for themselves and for the world," Trump told the annual gathering of 193 member nations and their representatives.

As U.S. president, he said he will "always put America first. Just like you, as the leaders of your countries, will always and should always put your countries first."

Applause in the room seemed to validate UN expert Richard Gowan's contention that sovereignty is, ironically, a "popular concept" at the world body.

Popular among whom, though, is potentially the problem.

"It's very popular with China. With Russia. And with developing countries in the Non-Aligned Movement," said Gowan, with the European Council on Foreign Relations. "It's appealing to a lot of the non-Western countries in the room."

Many of those nations have come under the scrutiny of international human rights observers.

'Leave us alone'

While Myanmar's leader, Aung San Suu Kyi, skipped this year's gathering amid allegations of ethnic cleansing of the Southeast Asian nation's Rohingya Muslims, Gowan said demands by any U.S. delegates that Myanmar stop the persecution could be thrown right back at the Americans.

"My suspicion is that U.S. diplomats who are going around trying to pressure Myanmar, or perhaps even Venezuela, will find that a lot of non-Western counterparts will say, 'We just heard your president praise sovereignty. We are simply sovereign nations — leave us alone.'"

Pundits pointed out after the speech that Russian President Vladimir Putin would delight in the prospect of an American president elevating national sovereignty above the promotion of democracy abroad.

"Trump has given a rhetorical gift to countries that are anti-liberal intervention and anti-human rights," Gowan said.

Russian President Vladimir Putin is one of many leaders at the UN with an admiration for the concept of sovereignty and a troubling human rights record. (Sputnik/Mikhail Klimentyev/Kremlin/Reuters)

Over the last decade, autocratic countries have asserted their sovereignty as a "shield" against criticisms from outside governments, said Gideon Maltz, a former deputy chief of staff to the U.S. ambassador to the UN. It gave them licence, he said, "to say very nakedly that they have the right to treat their citizens however they wish because that sovereignty trumps all else."

The U.S. has traditionally pushed back against that approach. Maltz believes Trump's speech could be seen as validating it.

"I don't know what President Trump intended," he said. "But there's significant risk a lot of governments will hear him pushing defence of sovereignty as supporting their position that governments matter, not citizens."

On that point, Louis Charbonneau, the UN director for Human Rights Watch, noted that Trump didn't hold back from condemning North Korea for the abuses and "starvation deaths of millions" of its citizens as well as slamming Syria for turning chemical weapons against its own people.

North Korea's UN ambassador, Ja Song Nam, leaves his seat prior to Trump's arrival. (Shannon Stapleton/Reuters)

One line in Trump's speech stressed the expectation that although nations must respect the rights of other sovereign nations, they must also "respect the interests of their own people."

"I'm not sure how out of sync that necessarily is from [traditional] U.S. policy," Charbonneau said. "But one thing we've learned from this administration is it's difficult to assess when the president is hinting at a change in policy."

Praise for Trump's message

That every nation would keep its own interests top of mind only makes sense, said Cliff May, president of the Foundation for Defense of Democracies, a conservative think-tank in Washington.

"But I also thought Trump made clear that his agenda assuring American sovereignty does not mean that the U.S. doesn't have shared interests and shared values with other nations, and that co-operation is possible."

Possible, that is, unless the U.S. moves toward a policy of isolationism. Trump has already withdrawn from the Paris climate accord and has threatened to pull out from the North American Free Trade Agreement. Trump on Tuesday called the Iran nuclear agreement an "embarrassment."

If the U.S. exits the deal, as Trump has hinted it might, it could further diminish the U.S. leadership role on the world stage.

Columbia University energy policy researcher Richard Nephew, who helped negotiate the original deal to prevent Iran from acquiring nuclear weapons in 2013-2015, fears it may soon come to that.

"What we still haven't heard from this administration is how they're going to solve the problem of Iran developing nuclear weapons by walking away from this deal," he said. "Until they make a decision on that, they're flying blind."

U.S. president decries Iran regime at United Nations 2:05

Nephew expects that Iran may carry forth with its obligations in the nuclear pact, with or without the Americans, giving the Islamic republic the opportunity to further isolate the U.S. from other Western powers and portray it as a "problem child."

Still, UN watchers such as Gowan found relief in Trump's remarks on Tuesday. While the president criticized bureaucratic bloat, there were no overt threats to withdraw U.S. funding.

And though Trump's words ridiculing North Korean dictator Kim Jong-un as "rocket man" and threatening annihilation of the rogue nation rang loudest over social media, the sound of clinking stemware after his speech celebrated what he toasted as the "tremendous potential" of the world body.

"There is no better forum, there can be no better forum," the president said, raising a glass at a luncheon.